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authordrh <drh@noemail.net>2013-06-26 13:31:50 +0000
committerdrh <drh@noemail.net>2013-06-26 13:31:50 +0000
commitfd64cedc4be4ec9e83fe37190bbc599ae232aaf2 (patch)
treeeb26e9fd9625f522104f3343c3dd77e9296f2fc7 /src
parent85b303df54a633e71380e3ffc0816ff952399b61 (diff)
parent989a6dbef118464509e7a303717fd0c61bbde1b8 (diff)
downloadsqlite-fd64cedc4be4ec9e83fe37190bbc599ae232aaf2.tar.gz
sqlite-fd64cedc4be4ec9e83fe37190bbc599ae232aaf2.zip
Bring the sessions branch up-to-date with all the latest trunk changes.
FossilOrigin-Name: 086a127236ee99d67513490fb7b5549e8b752c44
Diffstat (limited to 'src')
-rw-r--r--src/analyze.c2
-rw-r--r--src/backup.c6
-rw-r--r--src/btree.c4
-rw-r--r--src/build.c7
-rw-r--r--src/expr.c9
-rw-r--r--src/func.c8
-rw-r--r--src/main.c5
-rw-r--r--src/memjournal.c6
-rw-r--r--src/os_unix.c17
-rw-r--r--src/os_win.c23
-rw-r--r--src/pager.c42
-rw-r--r--src/parse.y2
-rw-r--r--src/pcache1.c2
-rw-r--r--src/pragma.c18
-rw-r--r--src/prepare.c4
-rw-r--r--src/printf.c6
-rw-r--r--src/select.c54
-rw-r--r--src/shell.c94
-rw-r--r--src/sqlite.h.in20
-rw-r--r--src/sqliteInt.h154
-rw-r--r--src/tclsqlite.c23
-rw-r--r--src/test1.c16
-rw-r--r--src/trigger.c2
-rw-r--r--src/update.c2
-rw-r--r--src/vdbe.c9
-rw-r--r--src/vdbeInt.h2
-rw-r--r--src/vdbeapi.c7
-rw-r--r--src/vdbeaux.c2
-rw-r--r--src/vdbesort.c2
-rw-r--r--src/where.c4527
30 files changed, 2674 insertions, 2401 deletions
diff --git a/src/analyze.c b/src/analyze.c
index 9a3e9597d..78bbf28b4 100644
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -25,7 +25,7 @@
** The sqlite_stat2 table is not created or used unless the SQLite version
** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled
** with SQLITE_ENABLE_STAT2. The sqlite_stat2 table is deprecated.
-** The sqlite_stat2 table is superceded by sqlite_stat3, which is only
+** The sqlite_stat2 table is superseded by sqlite_stat3, which is only
** created and used by SQLite versions 3.7.9 and later and with
** SQLITE_ENABLE_STAT3 defined. The fucntionality of sqlite_stat3
** is a superset of sqlite_stat2.
diff --git a/src/backup.c b/src/backup.c
index 252f61cfc..6ef9374ec 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -15,12 +15,6 @@
#include "sqliteInt.h"
#include "btreeInt.h"
-/* Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-
/*
** Structure allocated for each backup operation.
*/
diff --git a/src/btree.c b/src/btree.c
index 3ca60583e..f6e564628 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1215,7 +1215,7 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
}else if( gap+2<=top ){
/* Search the freelist looking for a free slot big enough to satisfy
** the request. The allocation is made from the first free slot in
- ** the list that is large enough to accomadate it.
+ ** the list that is large enough to accommodate it.
*/
int pc, addr;
for(addr=hdr+1; (pc = get2byte(&data[addr]))>0; addr=pc){
@@ -3158,7 +3158,7 @@ int sqlite3BtreeIncrVacuum(Btree *p){
/*
** This routine is called prior to sqlite3PagerCommit when a transaction
-** is commited for an auto-vacuum database.
+** is committed for an auto-vacuum database.
**
** If SQLITE_OK is returned, then *pnTrunc is set to the number of pages
** the database file should be truncated to during the commit process.
diff --git a/src/build.c b/src/build.c
index 3c91cdcfd..0a3922c95 100644
--- a/src/build.c
+++ b/src/build.c
@@ -1276,6 +1276,7 @@ void sqlite3AddCollateType(Parse *pParse, Token *pToken){
if( sqlite3LocateCollSeq(pParse, zColl) ){
Index *pIdx;
+ sqlite3DbFree(db, p->aCol[i].zColl);
p->aCol[i].zColl = zColl;
/* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
@@ -2695,6 +2696,7 @@ Index *sqlite3CreateIndex(
pIndex->pTable = pTab;
pIndex->nColumn = pList->nExpr;
pIndex->onError = (u8)onError;
+ pIndex->uniqNotNull = onError==OE_Abort;
pIndex->autoIndex = (u8)(pName==0);
pIndex->pSchema = db->aDb[iDb].pSchema;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
@@ -2753,6 +2755,7 @@ Index *sqlite3CreateIndex(
pIndex->azColl[i] = zColl;
requestedSortOrder = pListItem->sortOrder & sortOrderMask;
pIndex->aSortOrder[i] = (u8)requestedSortOrder;
+ if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0;
}
sqlite3DefaultRowEst(pIndex);
@@ -3184,7 +3187,7 @@ SrcList *sqlite3SrcListEnlarge(
}
pSrc = pNew;
nGot = (sqlite3DbMallocSize(db, pNew) - sizeof(*pSrc))/sizeof(pSrc->a[0])+1;
- pSrc->nAlloc = (u16)nGot;
+ pSrc->nAlloc = (u8)nGot;
}
/* Move existing slots that come after the newly inserted slots
@@ -3192,7 +3195,7 @@ SrcList *sqlite3SrcListEnlarge(
for(i=pSrc->nSrc-1; i>=iStart; i--){
pSrc->a[i+nExtra] = pSrc->a[i];
}
- pSrc->nSrc += (i16)nExtra;
+ pSrc->nSrc += (i8)nExtra;
/* Zero the newly allocated slots */
memset(&pSrc->a[iStart], 0, sizeof(pSrc->a[0])*nExtra);
diff --git a/src/expr.c b/src/expr.c
index 660397e07..2c0419aa2 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -920,6 +920,7 @@ ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
pItem->sortOrder = pOldItem->sortOrder;
pItem->done = 0;
+ pItem->bSpanIsTab = pOldItem->bSpanIsTab;
pItem->iOrderByCol = pOldItem->iOrderByCol;
pItem->iAlias = pOldItem->iAlias;
}
@@ -1596,15 +1597,15 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
/* Could not found an existing table or index to use as the RHS b-tree.
** We will have to generate an ephemeral table to do the job.
*/
- double savedNQueryLoop = pParse->nQueryLoop;
+ u32 savedNQueryLoop = pParse->nQueryLoop;
int rMayHaveNull = 0;
eType = IN_INDEX_EPH;
if( prNotFound ){
*prNotFound = rMayHaveNull = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
}else{
- testcase( pParse->nQueryLoop>(double)1 );
- pParse->nQueryLoop = (double)1;
+ testcase( pParse->nQueryLoop>0 );
+ pParse->nQueryLoop = 0;
if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
eType = IN_INDEX_ROWID;
}
@@ -1646,7 +1647,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
**
** If rMayHaveNull is zero, that means that the subquery is being used
** for membership testing only. There is no need to initialize any
-** registers to indicate the presense or absence of NULLs on the RHS.
+** registers to indicate the presence or absence of NULLs on the RHS.
**
** For a SELECT or EXISTS operator, return the register that holds the
** result. For IN operators or if an error occurs, the return value is 0.
diff --git a/src/func.c b/src/func.c
index e40fdad55..49f6c892b 100644
--- a/src/func.c
+++ b/src/func.c
@@ -228,7 +228,7 @@ static void instrFunc(
**
** If p1 is negative, then we begin abs(p1) from the end of x[].
**
-** If p2 is negative, return the p2 characters preceeding p1.
+** If p2 is negative, return the p2 characters preceding p1.
*/
static void substrFunc(
sqlite3_context *context,
@@ -887,10 +887,6 @@ static const char hexdigits[] = {
};
/*
-** EXPERIMENTAL - This is not an official function. The interface may
-** change. This function may disappear. Do not write code that depends
-** on this function.
-**
** Implementation of the QUOTE() function. This function takes a single
** argument. If the argument is numeric, the return value is the same as
** the argument. If the argument is NULL, the return value is the string
@@ -1079,7 +1075,7 @@ static void zeroblobFunc(
/*
** The replace() function. Three arguments are all strings: call
** them A, B, and C. The result is also a string which is derived
-** from A by replacing every occurance of B with C. The match
+** from A by replacing every occurrence of B with C. The match
** must be exact. Collating sequences are not used.
*/
static void replaceFunc(
diff --git a/src/main.c b/src/main.c
index 39ef5bfb5..6d3798dcb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -701,7 +701,7 @@ static int binCollFunc(
/*
** Another built-in collating sequence: NOCASE.
**
-** This collating sequence is intended to be used for "case independant
+** This collating sequence is intended to be used for "case independent
** comparison". SQLite's knowledge of upper and lower case equivalents
** extends only to the 26 characters used in the English language.
**
@@ -1024,7 +1024,6 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
inTrans = 1;
}
sqlite3BtreeRollback(p, tripCode);
- db->aDb[i].inTrans = 0;
}
}
sqlite3VtabRollback(db);
@@ -2812,8 +2811,6 @@ int sqlite3_global_recover(void){
** mode. Return TRUE if it is and FALSE if not. Autocommit mode is on
** by default. Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
-**
-******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
int sqlite3_get_autocommit(sqlite3 *db){
return db->autoCommit;
diff --git a/src/memjournal.c b/src/memjournal.c
index 05725948f..65ed378b3 100644
--- a/src/memjournal.c
+++ b/src/memjournal.c
@@ -31,12 +31,6 @@ typedef struct FileChunk FileChunk;
*/
#define JOURNAL_CHUNKSIZE ((int)(1024-sizeof(FileChunk*)))
-/* Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-
/*
** The rollback journal is composed of a linked list of these structures.
*/
diff --git a/src/os_unix.c b/src/os_unix.c
index abc23a452..152bf9a11 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -46,13 +46,6 @@
#include "sqliteInt.h"
#if SQLITE_OS_UNIX /* This file is used on unix only */
-/* Use posix_fallocate() if it is available
-*/
-#if !defined(HAVE_POSIX_FALLOCATE) \
- && (_XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L)
-# define HAVE_POSIX_FALLOCATE 1
-#endif
-
/*
** There are various methods for file locking used for concurrency
** control:
@@ -3775,15 +3768,19 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
}
case SQLITE_FCNTL_MMAP_SIZE: {
i64 newLimit = *(i64*)pArg;
+ int rc = SQLITE_OK;
if( newLimit>sqlite3GlobalConfig.mxMmap ){
newLimit = sqlite3GlobalConfig.mxMmap;
}
*(i64*)pArg = pFile->mmapSizeMax;
- if( newLimit>=0 ){
+ if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
pFile->mmapSizeMax = newLimit;
- if( newLimit<pFile->mmapSize ) pFile->mmapSize = newLimit;
+ if( pFile->mmapSize>0 ){
+ unixUnmapfile(pFile);
+ rc = unixMapfile(pFile, -1);
+ }
}
- return SQLITE_OK;
+ return rc;
}
#ifdef SQLITE_DEBUG
/* The pager calls this method to signal that it has done
diff --git a/src/os_win.c b/src/os_win.c
index aeb08814b..bdf025aa4 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -85,13 +85,6 @@ WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
#endif /* SQLITE_WIN32_FILEMAPPING_API && !defined(SQLITE_OMIT_WAL) */
/*
-** Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-
-/*
** Some Microsoft compilers lack this definition.
*/
#ifndef INVALID_FILE_ATTRIBUTES
@@ -2816,6 +2809,9 @@ static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
/* Forward declaration */
static int getTempname(int nBuf, char *zBuf);
+#if SQLITE_MAX_MMAP_SIZE>0
+static int winMapfile(winFile*, sqlite3_int64);
+#endif
/*
** Control and query of the open file handle.
@@ -2899,13 +2895,20 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
#if SQLITE_MAX_MMAP_SIZE>0
case SQLITE_FCNTL_MMAP_SIZE: {
i64 newLimit = *(i64*)pArg;
+ int rc = SQLITE_OK;
if( newLimit>sqlite3GlobalConfig.mxMmap ){
newLimit = sqlite3GlobalConfig.mxMmap;
}
*(i64*)pArg = pFile->mmapSizeMax;
- if( newLimit>=0 ) pFile->mmapSizeMax = newLimit;
- OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
- return SQLITE_OK;
+ if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
+ pFile->mmapSizeMax = newLimit;
+ if( pFile->mmapSize>0 ){
+ (void)winUnmapfile(pFile);
+ rc = winMapfile(pFile, -1);
+ }
+ }
+ OSTRACE(("FCNTL file=%p, rc=%d\n", pFile->h, rc));
+ return rc;
}
#endif
}
diff --git a/src/pager.c b/src/pager.c
index 1c6a84fea..645cc3d9a 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -4214,7 +4214,8 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
*/
assert( rc!=SQLITE_OK || isOpen(pPager->fd) );
if( rc==SQLITE_OK
- && (pList->pDirty ? pPager->dbSize : pList->pgno+1)>pPager->dbHintSize
+ && pPager->dbHintSize<pPager->dbSize
+ && (pList->pDirty || pList->pgno>pPager->dbHintSize)
){
sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
@@ -5179,7 +5180,7 @@ static void pagerUnlockIfUnused(Pager *pPager){
** page is initialized to all zeros.
**
** If noContent is true, it means that we do not care about the contents
-** of the page. This occurs in two seperate scenarios:
+** of the page. This occurs in two scenarios:
**
** a) When reading a free-list leaf page from the database, and
**
@@ -6589,7 +6590,27 @@ void sqlite3PagerSetCodec(
void *sqlite3PagerGetCodec(Pager *pPager){
return pPager->pCodec;
}
-#endif
+
+/*
+** This function is called by the wal module when writing page content
+** into the log file.
+**
+** This function returns a pointer to a buffer containing the encrypted
+** page content. If a malloc fails, this function may return NULL.
+*/
+void *sqlite3PagerCodec(PgHdr *pPg){
+ void *aData = 0;
+ CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
+ return aData;
+}
+
+/*
+** Return the current pager state
+*/
+int sqlite3PagerState(Pager *pPager){
+ return pPager->eState;
+}
+#endif /* SQLITE_HAS_CODEC */
#ifndef SQLITE_OMIT_AUTOVACUUM
/*
@@ -7144,19 +7165,4 @@ int sqlite3PagerWalFramesize(Pager *pPager){
}
#endif
-#ifdef SQLITE_HAS_CODEC
-/*
-** This function is called by the wal module when writing page content
-** into the log file.
-**
-** This function returns a pointer to a buffer containing the encrypted
-** page content. If a malloc fails, this function may return NULL.
-*/
-void *sqlite3PagerCodec(PgHdr *pPg){
- void *aData = 0;
- CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
- return aData;
-}
-#endif /* SQLITE_HAS_CODEC */
-
#endif /* SQLITE_OMIT_DISKIO */
diff --git a/src/parse.y b/src/parse.y
index 8310b2698..d707ee0a8 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -213,7 +213,7 @@ id(A) ::= INDEXED(X). {A = X;}
.
%wildcard ANY.
-// Define operator precedence early so that this is the first occurance
+// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer. Keeping the operators together
// causes them to be assigned integer values that are close together,
// which keeps parser tables smaller.
diff --git a/src/pcache1.c b/src/pcache1.c
index 4147d2eff..e06f5dae6 100644
--- a/src/pcache1.c
+++ b/src/pcache1.c
@@ -562,7 +562,7 @@ static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){
int sz; /* Bytes of memory required to allocate the new cache */
/*
- ** The seperateCache variable is true if each PCache has its own private
+ ** The separateCache variable is true if each PCache has its own private
** PGroup. In other words, separateCache is true for mode (1) where no
** mutexing is required.
**
diff --git a/src/pragma.c b/src/pragma.c
index 3056a7d8e..5803f6c4a 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -774,11 +774,15 @@ void sqlite3Pragma(
}
}
sz = -1;
- if( sqlite3_file_control(db,zDb,SQLITE_FCNTL_MMAP_SIZE,&sz)==SQLITE_OK ){
+ rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);
#if SQLITE_MAX_MMAP_SIZE==0
- sz = 0;
+ sz = 0;
#endif
+ if( rc==SQLITE_OK ){
returnSingleInt(pParse, "mmap_size", sz);
+ }else if( rc!=SQLITE_NOTFOUND ){
+ pParse->nErr++;
+ pParse->rc = rc;
}
}else
@@ -1309,7 +1313,7 @@ void sqlite3Pragma(
#endif
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
- /* Pragma "quick_check" is an experimental reduced version of
+ /* Pragma "quick_check" is reduced version of
** integrity_check designed to detect most database corruption
** without most of the overhead of a full integrity-check.
*/
@@ -1767,10 +1771,10 @@ void sqlite3Pragma(
#ifdef SQLITE_HAS_CODEC
if( sqlite3StrICmp(zLeft, "key")==0 && zRight ){
- sqlite3_key(db, zRight, sqlite3Strlen30(zRight));
+ sqlite3_key_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
}else
if( sqlite3StrICmp(zLeft, "rekey")==0 && zRight ){
- sqlite3_rekey(db, zRight, sqlite3Strlen30(zRight));
+ sqlite3_rekey_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
}else
if( zRight && (sqlite3StrICmp(zLeft, "hexkey")==0 ||
sqlite3StrICmp(zLeft, "hexrekey")==0) ){
@@ -1782,9 +1786,9 @@ void sqlite3Pragma(
zKey[i/2] = (h2 & 0x0f) | ((h1 & 0xf)<<4);
}
if( (zLeft[3] & 0xf)==0xb ){
- sqlite3_key(db, zKey, i/2);
+ sqlite3_key_v2(db, zDb, zKey, i/2);
}else{
- sqlite3_rekey(db, zKey, i/2);
+ sqlite3_rekey_v2(db, zDb, zKey, i/2);
}
}else
#endif
diff --git a/src/prepare.c b/src/prepare.c
index d78d83cbd..28145aa4e 100644
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -592,7 +592,7 @@ static int sqlite3Prepare(
sqlite3VtabUnlockList(db);
pParse->db = db;
- pParse->nQueryLoop = (double)1;
+ pParse->nQueryLoop = 0; /* Logarithmic, so 0 really means 1 */
if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
char *zSqlCopy;
int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
@@ -614,7 +614,7 @@ static int sqlite3Prepare(
}else{
sqlite3RunParser(pParse, zSql, &zErrMsg);
}
- assert( 1==(int)pParse->nQueryLoop );
+ assert( 0==pParse->nQueryLoop );
if( db->mallocFailed ){
pParse->rc = SQLITE_NOMEM;
diff --git a/src/printf.c b/src/printf.c
index 9f68d204f..8d37d633b 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -413,13 +413,7 @@ void sqlite3VXPrintf(
else prefix = 0;
}
if( xtype==etGENERIC && precision>0 ) precision--;
-#if 0
- /* Rounding works like BSD when the constant 0.4999 is used. Wierd! */
- for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
-#else
- /* It makes more sense to use 0.5 */
for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
-#endif
if( xtype==etFLOAT ) realvalue += rounder;
/* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
exp = 0;
diff --git a/src/select.c b/src/select.c
index f3f149096..fa35f4587 100644
--- a/src/select.c
+++ b/src/select.c
@@ -109,7 +109,7 @@ void sqlite3SelectDelete(sqlite3 *db, Select *p){
}
/*
-** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
+** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
** type of join. Return an integer constant that expresses that type
** in terms of the following bit values:
**
@@ -1523,7 +1523,7 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
/*
** "LIMIT -1" always shows all rows. There is some
- ** contraversy about what the correct behavior should be.
+ ** controversy about what the correct behavior should be.
** The current implementation interprets "LIMIT 0" to mean
** no rows.
*/
@@ -1538,8 +1538,8 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
VdbeComment((v, "LIMIT counter"));
if( n==0 ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);
- }else{
- if( p->nSelectRow > (double)n ) p->nSelectRow = (double)n;
+ }else if( n>=0 && p->nSelectRow>(u64)n ){
+ p->nSelectRow = n;
}
}else{
sqlite3ExprCode(pParse, p->pLimit, iLimit);
@@ -1733,9 +1733,9 @@ static int multiSelect(
p->nSelectRow += pPrior->nSelectRow;
if( pPrior->pLimit
&& sqlite3ExprIsInteger(pPrior->pLimit, &nLimit)
- && p->nSelectRow > (double)nLimit
+ && nLimit>0 && p->nSelectRow > (u64)nLimit
){
- p->nSelectRow = (double)nLimit;
+ p->nSelectRow = nLimit;
}
if( addr ){
sqlite3VdbeJumpHere(v, addr);
@@ -3884,11 +3884,10 @@ static void explainSimpleCount(
Index *pIdx /* Index used to optimize scan, or NULL */
){
if( pParse->explain==2 ){
- char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s %s%s(~%d rows)",
+ char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s%s%s",
pTab->zName,
- pIdx ? "USING COVERING INDEX " : "",
- pIdx ? pIdx->zName : "",
- pTab->nRowEst
+ pIdx ? " USING COVERING INDEX " : "",
+ pIdx ? pIdx->zName : ""
);
sqlite3VdbeAddOp4(
pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC
@@ -4046,7 +4045,7 @@ int sqlite3Select(
}
/* Increment Parse.nHeight by the height of the largest expression
- ** tree refered to by this, the parent select. The child select
+ ** tree referred to by this, the parent select. The child select
** may contain expression trees of at most
** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
** more conservative than necessary, but much easier than enforcing
@@ -4239,7 +4238,7 @@ int sqlite3Select(
/* Set the limiter.
*/
iEnd = sqlite3VdbeMakeLabel(v);
- p->nSelectRow = (double)LARGEST_INT64;
+ p->nSelectRow = LARGEST_INT64;
computeLimitRegisters(pParse, p, iEnd);
if( p->iLimit==0 && addrSortIndex>=0 ){
sqlite3VdbeGetOp(v, addrSortIndex)->opcode = OP_SorterOpen;
@@ -4262,14 +4261,19 @@ int sqlite3Select(
if( !isAgg && pGroupBy==0 ){
/* No aggregate functions and no GROUP BY clause */
- ExprList *pDist = (sDistinct.isTnct ? p->pEList : 0);
+ u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0);
/* Begin the database scan. */
- pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pOrderBy, pDist, 0,0);
+ pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pOrderBy, p->pEList,
+ wctrlFlags, 0);
if( pWInfo==0 ) goto select_end;
- if( pWInfo->nRowOut < p->nSelectRow ) p->nSelectRow = pWInfo->nRowOut;
- if( pWInfo->eDistinct ) sDistinct.eTnctType = pWInfo->eDistinct;
- if( pOrderBy && pWInfo->nOBSat==pOrderBy->nExpr ) pOrderBy = 0;
+ if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
+ p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
+ }
+ if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
+ sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
+ }
+ if( pOrderBy && sqlite3WhereIsOrdered(pWInfo) ) pOrderBy = 0;
/* If sorting index that was created by a prior OP_OpenEphemeral
** instruction ended up not being needed, then change the OP_OpenEphemeral
@@ -4282,7 +4286,8 @@ int sqlite3Select(
/* Use the standard inner loop. */
selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, &sDistinct, pDest,
- pWInfo->iContinue, pWInfo->iBreak);
+ sqlite3WhereContinueLabel(pWInfo),
+ sqlite3WhereBreakLabel(pWInfo));
/* End the database scan loop.
*/
@@ -4315,9 +4320,9 @@ int sqlite3Select(
for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
pItem->iAlias = 0;
}
- if( p->nSelectRow>(double)100 ) p->nSelectRow = (double)100;
+ if( p->nSelectRow>100 ) p->nSelectRow = 100;
}else{
- p->nSelectRow = (double)1;
+ p->nSelectRow = 1;
}
@@ -4397,9 +4402,10 @@ int sqlite3Select(
** in the right order to begin with.
*/
sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
- pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0, 0, 0);
+ pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,
+ WHERE_GROUPBY, 0);
if( pWInfo==0 ) goto select_end;
- if( pWInfo->nOBSat==pGroupBy->nExpr ){
+ if( sqlite3WhereIsOrdered(pWInfo) ){
/* The optimizer is able to deliver rows in group by order so
** we do not have to sort. The OP_OpenEphemeral table will be
** cancelled later because we still need to use the pKeyInfo
@@ -4680,8 +4686,8 @@ int sqlite3Select(
}
updateAccumulator(pParse, &sAggInfo);
assert( pMinMax==0 || pMinMax->nExpr==1 );
- if( pWInfo->nOBSat>0 ){
- sqlite3VdbeAddOp2(v, OP_Goto, 0, pWInfo->iBreak);
+ if( sqlite3WhereIsOrdered(pWInfo) ){
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3WhereBreakLabel(pWInfo));
VdbeComment((v, "%s() by index",
(flag==WHERE_ORDERBY_MIN?"min":"max")));
}
diff --git a/src/shell.c b/src/shell.c
index 1be2871fe..9a8a90694 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -1109,6 +1109,8 @@ static int display_stats(
fprintf(pArg->out, "Sort Operations: %d\n", iCur);
iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_AUTOINDEX, bReset);
fprintf(pArg->out, "Autoindex Inserts: %d\n", iCur);
+ iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP, bReset);
+ fprintf(pArg->out, "Virtual Machine Steps: %d\n", iCur);
}
return 0;
@@ -1523,21 +1525,14 @@ static void resolve_backslashes(char *z){
}
/*
-** Interpret zArg as a boolean value. Return either 0 or 1.
-*/
-static int booleanValue(char *zArg){
- int i;
- for(i=0; zArg[i]>='0' && zArg[i]<='9'; i++){}
- if( i>0 && zArg[i]==0 ) return atoi(zArg);
- if( sqlite3_stricmp(zArg, "on")==0 || sqlite3_stricmp(zArg,"yes")==0 ){
- return 1;
- }
- if( sqlite3_stricmp(zArg, "off")==0 || sqlite3_stricmp(zArg,"no")==0 ){
- return 0;
- }
- fprintf(stderr, "ERROR: Not a boolean value: \"%s\". Assuming \"no\".\n",
- zArg);
- return 0;
+** Return the value of a hexadecimal digit. Return -1 if the input
+** is not a hex digit.
+*/
+static int hexDigitValue(char c){
+ if( c>='0' && c<='9' ) return c - '0';
+ if( c>='a' && c<='f' ) return c - 'a' + 10;
+ if( c>='A' && c<='F' ) return c - 'A' + 10;
+ return -1;
}
/*
@@ -1564,11 +1559,20 @@ static sqlite3_int64 integerValue(const char *zArg){
}else if( zArg[0]=='+' ){
zArg++;
}
- while( isdigit(zArg[0]) ){
- v = v*10 + zArg[0] - '0';
- zArg++;
+ if( zArg[0]=='0' && zArg[1]=='x' ){
+ int x;
+ zArg += 2;
+ while( (x = hexDigitValue(zArg[0]))>=0 ){
+ v = (v<<4) + x;
+ zArg++;
+ }
+ }else{
+ while( IsDigit(zArg[0]) ){
+ v = v*10 + zArg[0] - '0';
+ zArg++;
+ }
}
- for(i=0; i<sizeof(aMult)/sizeof(aMult[0]); i++){
+ for(i=0; i<ArraySize(aMult); i++){
if( sqlite3_stricmp(aMult[i].zSuffix, zArg)==0 ){
v *= aMult[i].iMult;
break;
@@ -1578,6 +1582,29 @@ static sqlite3_int64 integerValue(const char *zArg){
}
/*
+** Interpret zArg as either an integer or a boolean value. Return 1 or 0
+** for TRUE and FALSE. Return the integer value if appropriate.
+*/
+static int booleanValue(char *zArg){
+ int i;
+ if( zArg[0]=='0' && zArg[1]=='x' ){
+ for(i=2; hexDigitValue(zArg[i])>=0; i++){}
+ }else{
+ for(i=0; zArg[i]>='0' && zArg[i]<='9'; i++){}
+ }
+ if( i>0 && zArg[i]==0 ) return (int)(integerValue(zArg) & 0xffffffff);
+ if( sqlite3_stricmp(zArg, "on")==0 || sqlite3_stricmp(zArg,"yes")==0 ){
+ return 1;
+ }
+ if( sqlite3_stricmp(zArg, "off")==0 || sqlite3_stricmp(zArg,"no")==0 ){
+ return 0;
+ }
+ fprintf(stderr, "ERROR: Not a boolean value: \"%s\". Assuming \"no\".\n",
+ zArg);
+ return 0;
+}
+
+/*
** Close an output file, assuming it is not stderr or stdout
*/
static void output_file_close(FILE *f){
@@ -1808,7 +1835,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
}else
if( c=='e' && strncmp(azArg[0], "exit", n)==0 ){
- if( nArg>1 && (rc = atoi(azArg[1]))!=0 ) exit(rc);
+ if( nArg>1 && (rc = (int)integerValue(azArg[1]))!=0 ) exit(rc);
rc = 2;
}else
@@ -2305,6 +2332,25 @@ static int do_meta_command(char *zLine, struct callback_data *p){
}
}else
+ /* Undocumented commands for internal testing. Subject to change
+ ** without notice. */
+ if( c=='s' && n>=10 && strncmp(azArg[0], "selftest-", 9)==0 ){
+ if( strncmp(azArg[0]+9, "boolean", n-9)==0 ){
+ int i, v;
+ for(i=1; i<nArg; i++){
+ v = booleanValue(azArg[i]);
+ fprintf(p->out, "%s: %d 0x%x\n", azArg[i], v, v);
+ }
+ }
+ if( strncmp(azArg[0]+9, "integer", n-9)==0 ){
+ int i; sqlite3_int64 v;
+ for(i=1; i<nArg; i++){
+ v = integerValue(azArg[i]);
+ fprintf(p->out, "%s: %lld 0x%llx\n", azArg[i], v, v);
+ }
+ }
+ }else
+
if( c=='s' && strncmp(azArg[0], "separator", n)==0 && nArg==2 ){
sqlite3_snprintf(sizeof(p->separator), p->separator,
"%.*s", (int)sizeof(p->separator)-1, azArg[1]);
@@ -2458,7 +2504,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
}
}
}
- if( testctrl<0 ) testctrl = atoi(azArg[1]);
+ if( testctrl<0 ) testctrl = (int)integerValue(azArg[1]);
if( (testctrl<SQLITE_TESTCTRL_FIRST) || (testctrl>SQLITE_TESTCTRL_LAST) ){
fprintf(stderr,"Error: invalid testctrl option: %s\n", azArg[1]);
}else{
@@ -2505,7 +2551,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
case SQLITE_TESTCTRL_ASSERT:
case SQLITE_TESTCTRL_ALWAYS:
if( nArg==3 ){
- int opt = atoi(azArg[2]);
+ int opt = booleanValue(azArg[2]);
rc = sqlite3_test_control(testctrl, opt);
fprintf(p->out, "%d (0x%08x)\n", rc, rc);
} else {
@@ -2542,7 +2588,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
if( c=='t' && n>4 && strncmp(azArg[0], "timeout", n)==0 && nArg==2 ){
open_db(p);
- sqlite3_busy_timeout(p->db, atoi(azArg[1]));
+ sqlite3_busy_timeout(p->db, (int)integerValue(azArg[1]));
}else
if( HAS_TIMER && c=='t' && n>=5 && strncmp(azArg[0], "timer", n)==0
@@ -2592,7 +2638,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
int j;
assert( nArg<=ArraySize(azArg) );
for(j=1; j<nArg && j<ArraySize(p->colWidth); j++){
- p->colWidth[j-1] = atoi(azArg[j]);
+ p->colWidth[j-1] = (int)integerValue(azArg[j]);
}
}else
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index e277185ff..3894e56ab 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -4513,6 +4513,11 @@ int sqlite3_key(
sqlite3 *db, /* Database to be rekeyed */
const void *pKey, int nKey /* The key */
);
+int sqlite3_key_v2(
+ sqlite3 *db, /* Database to be rekeyed */
+ const char *zDbName, /* Name of the database */
+ const void *pKey, int nKey /* The key */
+);
/*
** Change the key on an open database. If the current database is not
@@ -4526,6 +4531,11 @@ int sqlite3_rekey(
sqlite3 *db, /* Database to be rekeyed */
const void *pKey, int nKey /* The new key */
);
+int sqlite3_rekey_v2(
+ sqlite3 *db, /* Database to be rekeyed */
+ const char *zDbName, /* Name of the database */
+ const void *pKey, int nKey /* The new key */
+);
/*
** Specify the activation key for a SEE database. Unless
@@ -6293,11 +6303,21 @@ int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
** A non-zero value in this counter may indicate an opportunity to
** improvement performance by adding permanent indices that do not
** need to be reinitialized each time the statement is run.</dd>
+**
+** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
+** <dd>^This is the number of virtual machine operations executed
+** by the prepared statement if that number is less than or equal
+** to 2147483647. The number of virtual machine operations can be
+** used as a proxy for the total work done by the prepared statement.
+** If the number of virtual machine operations exceeds 2147483647
+** then the value returned by this statement status code is undefined.
+** </dd>
** </dl>
*/
#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
#define SQLITE_STMTSTATUS_SORT 2
#define SQLITE_STMTSTATUS_AUTOINDEX 3
+#define SQLITE_STMTSTATUS_VM_STEP 4
/*
** CAPI3REF: Custom Page Cache Object
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index e11e9ebf6..8ee07a13f 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -114,7 +114,7 @@
** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
** 0 means mutexes are permanently disable and the library is never
** threadsafe. 1 means the library is serialized which is the highest
-** level of threadsafety. 2 means the libary is multithreaded - multiple
+** level of threadsafety. 2 means the library is multithreaded - multiple
** threads can use SQLite as long as no two threads try to use the same
** database connection at the same time.
**
@@ -193,20 +193,12 @@
/*
** We need to define _XOPEN_SOURCE as follows in order to enable
-** recursive mutexes on most Unix systems. But Mac OS X is different.
-** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
-** so it is omitted there. See ticket #2673.
-**
-** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
-** implemented on some systems. So we avoid defining it at all
-** if it is already defined or if it is unneeded because we are
-** not doing a threadsafe build. Ticket #2681.
-**
-** See also ticket #2741.
+** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
+** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
+** it.
*/
-#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) \
- && !defined(__APPLE__) && SQLITE_THREADSAFE
-# define _XOPEN_SOURCE 500 /* Needed to enable pthread recursive mutexes */
+#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
+# define _XOPEN_SOURCE 600
#endif
/*
@@ -404,6 +396,12 @@
#endif
/*
+** Macros to compute minimum and maximum of two numbers.
+*/
+#define MIN(A,B) ((A)<(B)?(A):(B))
+#define MAX(A,B) ((A)>(B)?(A):(B))
+
+/*
** Check to see if this machine uses EBCDIC. (Yes, believe it or
** not, there are still machines out there that use EBCDIC.)
*/
@@ -729,9 +727,7 @@ typedef struct UnpackedRecord UnpackedRecord;
typedef struct VTable VTable;
typedef struct VtabCtx VtabCtx;
typedef struct Walker Walker;
-typedef struct WherePlan WherePlan;
typedef struct WhereInfo WhereInfo;
-typedef struct WhereLevel WhereLevel;
/*
** Defer sourcing vdbe.h and btree.h until after the "u8" and
@@ -757,7 +753,6 @@ typedef struct WhereLevel WhereLevel;
struct Db {
char *zName; /* Name of this database */
Btree *pBt; /* The B*Tree structure for this database file */
- u8 inTrans; /* 0: not writable. 1: Transaction. 2: Checkpoint */
u8 safety_level; /* How aggressive at syncing data to disk */
Schema *pSchema; /* Pointer to database schema (possibly shared) */
};
@@ -1037,6 +1032,7 @@ struct sqlite3 {
#define SQLITE_OrderByIdxJoin 0x0080 /* ORDER BY of joins via index */
#define SQLITE_SubqCoroutine 0x0100 /* Evaluate subqueries as coroutines */
#define SQLITE_Transitive 0x0200 /* Transitive constraints */
+#define SQLITE_OmitNoopJoin 0x0400 /* Omit unused tables in joins */
#define SQLITE_AllOpts 0xffff /* All optimizations */
/*
@@ -1562,6 +1558,7 @@ struct Index {
u8 onError; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
unsigned autoIndex:2; /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
unsigned bUnordered:1; /* Use this index for == or IN queries only */
+ unsigned uniqNotNull:1; /* True if UNIQUE and NOT NULL for all columns */
#ifdef SQLITE_ENABLE_STAT3
int nSample; /* Number of elements in aSample[] */
tRowcnt avgEq; /* Average nEq value for key values not in aSample */
@@ -1908,6 +1905,11 @@ typedef u64 Bitmask;
#define BMS ((int)(sizeof(Bitmask)*8))
/*
+** A bit in a Bitmask
+*/
+#define MASKBIT(n) (((Bitmask)1)<<(n))
+
+/*
** The following structure describes the FROM clause of a SELECT statement.
** Each table or subquery in the FROM clause is a separate element of
** the SrcList.a[] array.
@@ -1927,8 +1929,8 @@ typedef u64 Bitmask;
** contains more than 63 columns and the 64-th or later column is used.
*/
struct SrcList {
- i16 nSrc; /* Number of tables or subqueries in the FROM clause */
- i16 nAlloc; /* Number of entries allocated in a[] below */
+ u8 nSrc; /* Number of tables or subqueries in the FROM clause */
+ u8 nAlloc; /* Number of entries allocated in a[] below */
struct SrcList_item {
Schema *pSchema; /* Schema to which this item is fixed */
char *zDatabase; /* Name of database holding this table */
@@ -1967,79 +1969,6 @@ struct SrcList {
/*
-** A WherePlan object holds information that describes a lookup
-** strategy.
-**
-** This object is intended to be opaque outside of the where.c module.
-** It is included here only so that that compiler will know how big it
-** is. None of the fields in this object should be used outside of
-** the where.c module.
-**
-** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
-** pTerm is only used when wsFlags&WHERE_MULTI_OR is true. And pVtabIdx
-** is only used when wsFlags&WHERE_VIRTUALTABLE is true. It is never the
-** case that more than one of these conditions is true.
-*/
-struct WherePlan {
- u32 wsFlags; /* WHERE_* flags that describe the strategy */
- u16 nEq; /* Number of == constraints */
- u16 nOBSat; /* Number of ORDER BY terms satisfied */
- double nRow; /* Estimated number of rows (for EQP) */
- union {
- Index *pIdx; /* Index when WHERE_INDEXED is true */
- struct WhereTerm *pTerm; /* WHERE clause term for OR-search */
- sqlite3_index_info *pVtabIdx; /* Virtual table index to use */
- } u;
-};
-
-/*
-** For each nested loop in a WHERE clause implementation, the WhereInfo
-** structure contains a single instance of this structure. This structure
-** is intended to be private to the where.c module and should not be
-** access or modified by other modules.
-**
-** The pIdxInfo field is used to help pick the best index on a
-** virtual table. The pIdxInfo pointer contains indexing
-** information for the i-th table in the FROM clause before reordering.
-** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
-** All other information in the i-th WhereLevel object for the i-th table
-** after FROM clause ordering.
-*/
-struct WhereLevel {
- WherePlan plan; /* query plan for this element of the FROM clause */
- int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
- int iTabCur; /* The VDBE cursor used to access the table */
- int iIdxCur; /* The VDBE cursor used to access pIdx */
- int addrBrk; /* Jump here to break out of the loop */
- int addrNxt; /* Jump here to start the next IN combination */
- int addrCont; /* Jump here to continue with the next loop cycle */
- int addrFirst; /* First instruction of interior of the loop */
- u8 iFrom; /* Which entry in the FROM clause */
- u8 op, p5; /* Opcode and P5 of the opcode that ends the loop */
- int p1, p2; /* Operands of the opcode used to ends the loop */
- union { /* Information that depends on plan.wsFlags */
- struct {
- int nIn; /* Number of entries in aInLoop[] */
- struct InLoop {
- int iCur; /* The VDBE cursor used by this IN operator */
- int addrInTop; /* Top of the IN loop */
- u8 eEndLoopOp; /* IN Loop terminator. OP_Next or OP_Prev */
- } *aInLoop; /* Information about each nested IN operator */
- } in; /* Used when plan.wsFlags&WHERE_IN_ABLE */
- Index *pCovidx; /* Possible covering index for WHERE_MULTI_OR */
- } u;
- double rOptCost; /* "Optimal" cost for this level */
-
- /* The following field is really not part of the current level. But
- ** we need a place to cache virtual table index information for each
- ** virtual table in the FROM clause and the WhereLevel structure is
- ** a convenient place since there is one WhereLevel for each FROM clause
- ** element.
- */
- sqlite3_index_info *pIdxInfo; /* Index info for n-th source table */
-};
-
-/*
** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
** and the WhereInfo.wctrlFlags member.
*/
@@ -2052,33 +1981,12 @@ struct WhereLevel {
#define WHERE_FORCE_TABLE 0x0020 /* Do not use an index-only search */
#define WHERE_ONETABLE_ONLY 0x0040 /* Only code the 1st table in pTabList */
#define WHERE_AND_ONLY 0x0080 /* Don't use indices for OR terms */
+#define WHERE_GROUPBY 0x0100 /* pOrderBy is really a GROUP BY */
+#define WHERE_DISTINCTBY 0x0200 /* pOrderby is really a DISTINCT clause */
+#define WHERE_WANT_DISTINCT 0x0400 /* All output needs to be distinct */
-/*
-** The WHERE clause processing routine has two halves. The
-** first part does the start of the WHERE loop and the second
-** half does the tail of the WHERE loop. An instance of
-** this structure is returned by the first half and passed
-** into the second half to give some continuity.
-*/
-struct WhereInfo {
- Parse *pParse; /* Parsing and code generating context */
- SrcList *pTabList; /* List of tables in the join */
- u16 nOBSat; /* Number of ORDER BY terms satisfied by indices */
- u16 wctrlFlags; /* Flags originally passed to sqlite3WhereBegin() */
- u8 okOnePass; /* Ok to use one-pass algorithm for UPDATE/DELETE */
- u8 untestedTerms; /* Not all WHERE terms resolved by outer loop */
- u8 eDistinct; /* One of the WHERE_DISTINCT_* values below */
- int iTop; /* The very beginning of the WHERE loop */
- int iContinue; /* Jump here to continue with next record */
- int iBreak; /* Jump here to break out of the loop */
- int nLevel; /* Number of nested loop */
- struct WhereClause *pWC; /* Decomposition of the WHERE clause */
- double savedNQueryLoop; /* pParse->nQueryLoop outside the WHERE loop */
- double nRowOut; /* Estimated number of output rows */
- WhereLevel a[1]; /* Information about each nest loop in WHERE */
-};
-
-/* Allowed values for WhereInfo.eDistinct and DistinctCtx.eTnctType */
+/* Allowed return values from sqlite3WhereIsDistinct()
+*/
#define WHERE_DISTINCT_NOOP 0 /* DISTINCT keyword not used */
#define WHERE_DISTINCT_UNIQUE 1 /* No duplicates */
#define WHERE_DISTINCT_ORDERED 2 /* All duplicates are adjacent */
@@ -2152,7 +2060,7 @@ struct Select {
u16 selFlags; /* Various SF_* values */
int iLimit, iOffset; /* Memory registers holding LIMIT & OFFSET counters */
int addrOpenEphm[3]; /* OP_OpenEphem opcodes related to this select */
- double nSelectRow; /* Estimated number of result rows */
+ u64 nSelectRow; /* Estimated number of result rows */
SrcList *pSrc; /* The FROM clause */
Expr *pWhere; /* The WHERE clause */
ExprList *pGroupBy; /* The GROUP BY clause */
@@ -2336,7 +2244,7 @@ struct Parse {
/* Information used while coding trigger programs. */
Parse *pToplevel; /* Parse structure for main program (or NULL) */
Table *pTriggerTab; /* Table triggers are being coded for */
- double nQueryLoop; /* Estimated number of iterations of a query */
+ u32 nQueryLoop; /* Est number of iterations of a query (10*log2(N)) */
u32 oldmask; /* Mask of old.* columns referenced */
u32 newmask; /* Mask of new.* columns referenced */
u8 eTriggerOp; /* TK_UPDATE, TK_INSERT or TK_DELETE */
@@ -2910,6 +2818,12 @@ void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
void sqlite3WhereEnd(WhereInfo*);
+u64 sqlite3WhereOutputRowCount(WhereInfo*);
+int sqlite3WhereIsDistinct(WhereInfo*);
+int sqlite3WhereIsOrdered(WhereInfo*);
+int sqlite3WhereContinueLabel(WhereInfo*);
+int sqlite3WhereBreakLabel(WhereInfo*);
+int sqlite3WhereOkOnePass(WhereInfo*);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int, int);
diff --git a/src/tclsqlite.c b/src/tclsqlite.c
index 9bd111d94..78a03083b 100644
--- a/src/tclsqlite.c
+++ b/src/tclsqlite.c
@@ -3196,7 +3196,7 @@ static int DbMain(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
*/
#ifndef USE_TCL_STUBS
# undef Tcl_InitStubs
-# define Tcl_InitStubs(a,b,c)
+# define Tcl_InitStubs(a,b,c) TCL_VERSION
#endif
/*
@@ -3220,19 +3220,18 @@ static int DbMain(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
** The EXTERN macros are required by TCL in order to work on windows.
*/
EXTERN int Sqlite3_Init(Tcl_Interp *interp){
- Tcl_InitStubs(interp, "8.4", 0);
- Tcl_CreateObjCommand(interp, "sqlite3", (Tcl_ObjCmdProc*)DbMain, 0, 0);
- Tcl_PkgProvide(interp, "sqlite3", PACKAGE_VERSION);
-
+ int rc = Tcl_InitStubs(interp, "8.4", 0)==0 ? TCL_ERROR : TCL_OK;
+ if( rc==TCL_OK ){
+ Tcl_CreateObjCommand(interp, "sqlite3", (Tcl_ObjCmdProc*)DbMain, 0, 0);
#ifndef SQLITE_3_SUFFIX_ONLY
- /* The "sqlite" alias is undocumented. It is here only to support
- ** legacy scripts. All new scripts should use only the "sqlite3"
- ** command.
- */
- Tcl_CreateObjCommand(interp, "sqlite", (Tcl_ObjCmdProc*)DbMain, 0, 0);
+ /* The "sqlite" alias is undocumented. It is here only to support
+ ** legacy scripts. All new scripts should use only the "sqlite3"
+ ** command. */
+ Tcl_CreateObjCommand(interp, "sqlite", (Tcl_ObjCmdProc*)DbMain, 0, 0);
#endif
-
- return TCL_OK;
+ rc = Tcl_PkgProvide(interp, "sqlite3", PACKAGE_VERSION);
+ }
+ return rc;
}
EXTERN int Tclsqlite3_Init(Tcl_Interp *interp){ return Sqlite3_Init(interp); }
EXTERN int Sqlite3_Unload(Tcl_Interp *interp, int flags){ return TCL_OK; }
diff --git a/src/test1.c b/src/test1.c
index a638e480a..58cfd2ca5 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -2218,6 +2218,7 @@ static int test_stmt_status(
{ "SQLITE_STMTSTATUS_FULLSCAN_STEP", SQLITE_STMTSTATUS_FULLSCAN_STEP },
{ "SQLITE_STMTSTATUS_SORT", SQLITE_STMTSTATUS_SORT },
{ "SQLITE_STMTSTATUS_AUTOINDEX", SQLITE_STMTSTATUS_AUTOINDEX },
+ { "SQLITE_STMTSTATUS_VM_STEP", SQLITE_STMTSTATUS_VM_STEP },
};
if( objc!=4 ){
Tcl_WrongNumArgs(interp, 1, objv, "STMT PARAMETER RESETFLAG");
@@ -2469,7 +2470,7 @@ static int sqlite_static_bind_nbyte = 0;
/*
** Usage: sqlite3_bind VM IDX VALUE FLAGS
**
-** Sets the value of the IDX-th occurance of "?" in the original SQL
+** Sets the value of the IDX-th occurrence of "?" in the original SQL
** string. VALUE is the new value. If FLAGS=="null" then VALUE is
** ignored and the value is set to NULL. If FLAGS=="static" then
** the value is set to the value of a static variable named
@@ -5563,7 +5564,7 @@ static int test_wal_checkpoint(
**
** Otherwise, this command returns a list of three integers. The first integer
** is 1 if SQLITE_BUSY was returned, or 0 otherwise. The following two integers
-** are the values returned via the output paramaters by wal_checkpoint_v2() -
+** are the values returned via the output parameters by wal_checkpoint_v2() -
** the number of frames in the log and the number of frames in the log
** that have been checkpointed.
*/
@@ -6012,6 +6013,7 @@ static int tclLoadStaticExtensionCmd(
extern int sqlite3_fuzzer_init(sqlite3*,char**,const sqlite3_api_routines*);
extern int sqlite3_ieee_init(sqlite3*,char**,const sqlite3_api_routines*);
extern int sqlite3_nextchar_init(sqlite3*,char**,const sqlite3_api_routines*);
+ extern int sqlite3_percentile_init(sqlite3*,char**,const sqlite3_api_routines*);
extern int sqlite3_regexp_init(sqlite3*,char**,const sqlite3_api_routines*);
extern int sqlite3_spellfix_init(sqlite3*,char**,const sqlite3_api_routines*);
extern int sqlite3_wholenumber_init(sqlite3*,char**,const sqlite3_api_routines*);
@@ -6024,6 +6026,7 @@ static int tclLoadStaticExtensionCmd(
{ "fuzzer", sqlite3_fuzzer_init },
{ "ieee754", sqlite3_ieee_init },
{ "nextchar", sqlite3_nextchar_init },
+ { "percentile", sqlite3_percentile_init },
{ "regexp", sqlite3_regexp_init },
{ "spellfix", sqlite3_spellfix_init },
{ "wholenumber", sqlite3_wholenumber_init },
@@ -6300,8 +6303,6 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
extern int sqlite3WalTrace;
#endif
#ifdef SQLITE_TEST
- extern char sqlite3_query_plan[];
- static char *query_plan = sqlite3_query_plan;
#ifdef SQLITE_ENABLE_FTS3
extern int sqlite3_fts3_enable_parentheses;
#endif
@@ -6355,8 +6356,11 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
(char*)&sqlite3_os_type, TCL_LINK_INT);
#endif
#ifdef SQLITE_TEST
- Tcl_LinkVar(interp, "sqlite_query_plan",
- (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+ {
+ static const char *query_plan = "*** OBSOLETE VARIABLE ***";
+ Tcl_LinkVar(interp, "sqlite_query_plan",
+ (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+ }
#endif
#ifdef SQLITE_DEBUG
Tcl_LinkVar(interp, "sqlite_where_trace",
diff --git a/src/trigger.c b/src/trigger.c
index f1ff766e2..b901d0767 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -1002,7 +1002,7 @@ void sqlite3CodeRowTriggerDirect(
/*
** This is called to code the required FOR EACH ROW triggers for an operation
** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)
-** is given by the op paramater. The tr_tm parameter determines whether the
+** is given by the op parameter. The tr_tm parameter determines whether the
** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then
** parameter pChanges is passed the list of columns being modified.
**
diff --git a/src/update.c b/src/update.c
index 0e8ac972e..7511c7916 100644
--- a/src/update.c
+++ b/src/update.c
@@ -318,7 +318,7 @@ void sqlite3Update(
pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, 0
);
if( pWInfo==0 ) goto update_cleanup;
- okOnePass = pWInfo->okOnePass;
+ okOnePass = sqlite3WhereOkOnePass(pWInfo);
/* Remember the rowid of every item to be updated.
*/
diff --git a/src/vdbe.c b/src/vdbe.c
index aa82a683e..c5e6cfcc3 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -566,12 +566,13 @@ int sqlite3VdbeExec(
int checkProgress; /* True if progress callbacks are enabled */
int nProgressOps = 0; /* Opcodes executed since progress callback. */
#endif
+ int iCompare = 0; /* Result of last OP_Compare operation */
+ unsigned nVmStep = 0; /* Number of virtual machine steps */
Mem *aMem = p->aMem; /* Copy of p->aMem */
Mem *pIn1 = 0; /* 1st input operand */
Mem *pIn2 = 0; /* 2nd input operand */
Mem *pIn3 = 0; /* 3rd input operand */
Mem *pOut = 0; /* Output operand */
- int iCompare = 0; /* Result of last OP_Compare operation */
int *aPermute = 0; /* Permutation of columns for OP_Compare */
i64 lastRowid = db->lastRowid; /* Saved value of the last insert ROWID */
#ifdef VDBE_PROFILE
@@ -616,6 +617,7 @@ int sqlite3VdbeExec(
origPc = pc;
start = sqlite3Hwtime();
#endif
+ nVmStep++;
pOp = &aOp[pc];
/* Only allow tracing if SQLITE_DEBUG is defined.
@@ -2924,8 +2926,8 @@ case OP_AutoCommit: {
** other process can start another write transaction while this transaction is
** underway. Starting a write transaction also creates a rollback journal. A
** write transaction must be started before any changes can be made to the
-** database. If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
-** on the file.
+** database. If P2 is greater than or equal to 2 then an EXCLUSIVE lock is
+** also obtained on the file.
**
** If a write-transaction is started and the Vdbe.usesStmtJournal flag is
** true (this flag is set if the Vdbe may modify more than one row and may
@@ -6252,6 +6254,7 @@ vdbe_error_halt:
** top. */
vdbe_return:
db->lastRowid = lastRowid;
+ p->aCounter[SQLITE_STMTSTATUS_VM_STEP-1] += (int)nVmStep;
sqlite3VdbeLeave(p);
return rc;
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index b1e637b32..1f9358a23 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -344,7 +344,7 @@ struct Vdbe {
yDbMask btreeMask; /* Bitmask of db->aDb[] entries referenced */
yDbMask lockMask; /* Subset of btreeMask that requires a lock */
int iStatement; /* Statement number (or 0 if has not opened stmt) */
- int aCounter[3]; /* Counters used by sqlite3_stmt_status() */
+ int aCounter[4]; /* Counters used by sqlite3_stmt_status() */
#ifndef SQLITE_OMIT_TRACE
i64 startTime; /* Time when query started - used for profiling */
#endif
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 61041237d..8be71383b 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -833,13 +833,6 @@ int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
return iType;
}
-/* The following function is experimental and subject to change or
-** removal */
-/*int sqlite3_column_numeric_type(sqlite3_stmt *pStmt, int i){
-** return sqlite3_value_numeric_type( columnMem(pStmt,i) );
-**}
-*/
-
/*
** Convert the N-th element of pStmt->pColName[] into a string using
** xFunc() then return that string. If N is out of range, return 0.
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 815146732..7897116fb 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -1997,7 +1997,7 @@ static void checkActiveVdbeCnt(sqlite3 *db){
** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the
-** statement transaction is commtted.
+** statement transaction is committed.
**
** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned.
** Otherwise SQLITE_OK.
diff --git a/src/vdbesort.c b/src/vdbesort.c
index fdfc4a79d..c8709bdaf 100644
--- a/src/vdbesort.c
+++ b/src/vdbesort.c
@@ -54,7 +54,7 @@ typedef struct FileWriter FileWriter;
** other key value. If the keys are equal (only possible with two EOF
** values), it doesn't matter which index is stored.
**
-** The (N/4) elements of aTree[] that preceed the final (N/2) described
+** The (N/4) elements of aTree[] that precede the final (N/2) described
** above contains the index of the smallest of each block of 4 iterators.
** And so on. So that aTree[1] contains the index of the iterator that
** currently points to the smallest key value. aTree[0] is unused.
diff --git a/src/where.c b/src/where.c
index e614f4a6d..e20f2b301 100644
--- a/src/where.c
+++ b/src/where.c
@@ -27,9 +27,10 @@
#endif
#if defined(SQLITE_DEBUG) \
&& (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
-# define WHERETRACE(X) if(sqlite3WhereTrace) sqlite3DebugPrintf X
+# define WHERETRACE(K,X) if(sqlite3WhereTrace&(K)) sqlite3DebugPrintf X
+# define WHERETRACE_ENABLED 1
#else
-# define WHERETRACE(X)
+# define WHERETRACE(K,X)
#endif
/* Forward reference
@@ -38,7 +39,149 @@ typedef struct WhereClause WhereClause;
typedef struct WhereMaskSet WhereMaskSet;
typedef struct WhereOrInfo WhereOrInfo;
typedef struct WhereAndInfo WhereAndInfo;
-typedef struct WhereCost WhereCost;
+typedef struct WhereLevel WhereLevel;
+typedef struct WhereLoop WhereLoop;
+typedef struct WherePath WherePath;
+typedef struct WhereTerm WhereTerm;
+typedef struct WhereLoopBuilder WhereLoopBuilder;
+typedef struct WhereScan WhereScan;
+
+/*
+** Cost X is tracked as 10*log2(X) stored in a 16-bit integer. The
+** maximum cost for ordinary tables is 64*(2**63) which becomes 6900.
+** (Virtual tables can return a larger cost, but let's assume they do not.)
+** So all costs can be stored in a 16-bit unsigned integer without risk
+** of overflow.
+**
+** Costs are estimates, so don't go to the computational trouble to compute
+** 10*log2(X) exactly. Instead, a close estimate is used. Any value of
+** X<=1 is stored as 0. X=2 is 10. X=3 is 16. X=1000 is 99. etc.
+**
+** The tool/wherecosttest.c source file implements a command-line program
+** that will convert between WhereCost to integers and do addition and
+** multiplication on WhereCost values. That command-line program is a
+** useful utility to have around when working with this module.
+*/
+typedef unsigned short int WhereCost;
+
+/*
+** This object contains information needed to implement a single nested
+** loop in WHERE clause.
+**
+** Contrast this object with WhereLoop. This object describes the
+** implementation of the loop. WhereLoop describes the algorithm.
+** This object contains a pointer to the WhereLoop algorithm as one of
+** its elements.
+**
+** The WhereInfo object contains a single instance of this object for
+** each term in the FROM clause (which is to say, for each of the
+** nested loops as implemented). The order of WhereLevel objects determines
+** the loop nested order, with WhereInfo.a[0] being the outer loop and
+** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
+*/
+struct WhereLevel {
+ int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
+ int iTabCur; /* The VDBE cursor used to access the table */
+ int iIdxCur; /* The VDBE cursor used to access pIdx */
+ int addrBrk; /* Jump here to break out of the loop */
+ int addrNxt; /* Jump here to start the next IN combination */
+ int addrCont; /* Jump here to continue with the next loop cycle */
+ int addrFirst; /* First instruction of interior of the loop */
+ u8 iFrom; /* Which entry in the FROM clause */
+ u8 op, p5; /* Opcode and P5 of the opcode that ends the loop */
+ int p1, p2; /* Operands of the opcode used to ends the loop */
+ union { /* Information that depends on pWLoop->wsFlags */
+ struct {
+ int nIn; /* Number of entries in aInLoop[] */
+ struct InLoop {
+ int iCur; /* The VDBE cursor used by this IN operator */
+ int addrInTop; /* Top of the IN loop */
+ u8 eEndLoopOp; /* IN Loop terminator. OP_Next or OP_Prev */
+ } *aInLoop; /* Information about each nested IN operator */
+ } in; /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
+ Index *pCovidx; /* Possible covering index for WHERE_MULTI_OR */
+ } u;
+ struct WhereLoop *pWLoop; /* The selected WhereLoop object */
+};
+
+/*
+** Each instance of this object represents an algorithm for evaluating one
+** term of a join. Every term of the FROM clause will have at least
+** one corresponding WhereLoop object (unless INDEXED BY constraints
+** prevent a query solution - which is an error) and many terms of the
+** FROM clause will have multiple WhereLoop objects, each describing a
+** potential way of implementing that FROM-clause term, together with
+** dependencies and cost estimates for using the chosen algorithm.
+**
+** Query planning consists of building up a collection of these WhereLoop
+** objects, then computing a particular sequence of WhereLoop objects, with
+** one WhereLoop object per FROM clause term, that satisfy all dependencies
+** and that minimize the overall cost.
+*/
+struct WhereLoop {
+ Bitmask prereq; /* Bitmask of other loops that must run first */
+ Bitmask maskSelf; /* Bitmask identifying table iTab */
+#ifdef SQLITE_DEBUG
+ char cId; /* Symbolic ID of this loop for debugging use */
+#endif
+ u8 iTab; /* Position in FROM clause of table for this loop */
+ u8 iSortIdx; /* Sorting index number. 0==None */
+ WhereCost rSetup; /* One-time setup cost (ex: create transient index) */
+ WhereCost rRun; /* Cost of running each loop */
+ WhereCost nOut; /* Estimated number of output rows */
+ union {
+ struct { /* Information for internal btree tables */
+ int nEq; /* Number of equality constraints */
+ Index *pIndex; /* Index used, or NULL */
+ } btree;
+ struct { /* Information for virtual tables */
+ int idxNum; /* Index number */
+ u8 needFree; /* True if sqlite3_free(idxStr) is needed */
+ u8 isOrdered; /* True if satisfies ORDER BY */
+ u16 omitMask; /* Terms that may be omitted */
+ char *idxStr; /* Index identifier string */
+ } vtab;
+ } u;
+ u32 wsFlags; /* WHERE_* flags describing the plan */
+ u16 nLTerm; /* Number of entries in aLTerm[] */
+ /**** whereLoopXfer() copies fields above ***********************/
+# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
+ u16 nLSlot; /* Number of slots allocated for aLTerm[] */
+ WhereTerm **aLTerm; /* WhereTerms used */
+ WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
+ WhereTerm *aLTermSpace[4]; /* Initial aLTerm[] space */
+};
+
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/*
+** Each instance of this object holds a sequence of WhereLoop objects
+** that implement some or all of a query plan.
+**
+** Think of each WhereLoop objects as a node in a graph, which arcs
+** showing dependences and costs for travelling between nodes. (That is
+** not a completely accurate description because WhereLoop costs are a
+** vector, not a scalar, and because dependences are many-to-one, not
+** one-to-one as are graph nodes. But it is a useful visualization aid.)
+** Then a WherePath object is a path through the graph that visits some
+** or all of the WhereLoop objects once.
+**
+** The "solver" works by creating the N best WherePath objects of length
+** 1. Then using those as a basis to compute the N best WherePath objects
+** of length 2. And so forth until the length of WherePaths equals the
+** number of nodes in the FROM clause. The best (lowest cost) WherePath
+** at the end is the choosen query plan.
+*/
+struct WherePath {
+ Bitmask maskLoop; /* Bitmask of all WhereLoop objects in this path */
+ Bitmask revLoop; /* aLoop[]s that should be reversed for ORDER BY */
+ WhereCost nRow; /* Estimated number of rows generated by this path */
+ WhereCost rCost; /* Total cost of this path */
+ u8 isOrdered; /* True if this path satisfies ORDER BY */
+ u8 isOrderedValid; /* True if the isOrdered field is valid */
+ WhereLoop **aLoop; /* Array of WhereLoop objects implementing this path */
+};
/*
** The query generator uses an array of instances of this structure to
@@ -91,7 +234,6 @@ typedef struct WhereCost WhereCost;
** in prereqRight and prereqAll. The default is 64 bits, hence SQLite
** is only able to process joins with 64 or fewer tables.
*/
-typedef struct WhereTerm WhereTerm;
struct WhereTerm {
Expr *pExpr; /* Pointer to the subexpression that is this term */
int iParent; /* Disable pWC->a[iParent] when this term disabled */
@@ -126,6 +268,22 @@ struct WhereTerm {
#endif
/*
+** An instance of the WhereScan object is used as an iterator for locating
+** terms in the WHERE clause that are useful to the query planner.
+*/
+struct WhereScan {
+ WhereClause *pOrigWC; /* Original, innermost WhereClause */
+ WhereClause *pWC; /* WhereClause currently being scanned */
+ char *zCollName; /* Required collating sequence, if not NULL */
+ char idxaff; /* Must match this affinity, if zCollName!=NULL */
+ unsigned char nEquiv; /* Number of entries in aEquiv[] */
+ unsigned char iEquiv; /* Next unused slot in aEquiv[] */
+ u32 opMask; /* Acceptable operators */
+ int k; /* Resume scanning at this->pWC->a[this->k] */
+ int aEquiv[22]; /* Cursor,Column pairs for equivalence classes */
+};
+
+/*
** An instance of the following structure holds all information about a
** WHERE clause. Mostly this is a container for one or more WhereTerms.
**
@@ -138,11 +296,9 @@ struct WhereTerm {
** subclauses points to the WhereClause object for the whole clause.
*/
struct WhereClause {
- Parse *pParse; /* The parser context */
- WhereMaskSet *pMaskSet; /* Mapping of table cursor numbers to bitmasks */
+ WhereInfo *pWInfo; /* WHERE clause processing context */
WhereClause *pOuter; /* Outer conjunction */
u8 op; /* Split operator. TK_AND or TK_OR */
- u16 wctrlFlags; /* Might include WHERE_AND_ONLY */
int nTerm; /* Number of terms */
int nSlot; /* Number of entries in a[] */
WhereTerm *a; /* Each a[] describes a term of the WHERE cluase */
@@ -202,19 +358,55 @@ struct WhereMaskSet {
};
/*
-** A WhereCost object records a lookup strategy and the estimated
-** cost of pursuing that strategy.
+** This object is a convenience wrapper holding all information needed
+** to construct WhereLoop objects for a particular query.
*/
-struct WhereCost {
- WherePlan plan; /* The lookup strategy */
- double rCost; /* Overall cost of pursuing this search strategy */
- Bitmask used; /* Bitmask of cursors used by this plan */
+struct WhereLoopBuilder {
+ WhereInfo *pWInfo; /* Information about this WHERE */
+ WhereClause *pWC; /* WHERE clause terms */
+ ExprList *pOrderBy; /* ORDER BY clause */
+ WhereLoop *pNew; /* Template WhereLoop */
+ WhereLoop *pBest; /* If non-NULL, store single best loop here */
};
/*
-** Bitmasks for the operators that indices are able to exploit. An
+** The WHERE clause processing routine has two halves. The
+** first part does the start of the WHERE loop and the second
+** half does the tail of the WHERE loop. An instance of
+** this structure is returned by the first half and passed
+** into the second half to give some continuity.
+**
+** An instance of this object holds the complete state of the query
+** planner.
+*/
+struct WhereInfo {
+ Parse *pParse; /* Parsing and code generating context */
+ SrcList *pTabList; /* List of tables in the join */
+ ExprList *pOrderBy; /* The ORDER BY clause or NULL */
+ ExprList *pResultSet; /* Result set. DISTINCT operates on these */
+ WhereLoop *pLoops; /* List of all WhereLoop objects */
+ Bitmask revMask; /* Mask of ORDER BY terms that need reversing */
+ WhereCost nRowOut; /* Estimated number of output rows */
+ u16 wctrlFlags; /* Flags originally passed to sqlite3WhereBegin() */
+ u8 bOBSat; /* ORDER BY satisfied by indices */
+ u8 okOnePass; /* Ok to use one-pass algorithm for UPDATE/DELETE */
+ u8 untestedTerms; /* Not all WHERE terms resolved by outer loop */
+ u8 eDistinct; /* One of the WHERE_DISTINCT_* values below */
+ u8 nLevel; /* Number of nested loop */
+ int iTop; /* The very beginning of the WHERE loop */
+ int iContinue; /* Jump here to continue with next record */
+ int iBreak; /* Jump here to break out of the loop */
+ int savedNQueryLoop; /* pParse->nQueryLoop outside the WHERE loop */
+ WhereMaskSet sMaskSet; /* Map cursor numbers to bitmasks */
+ WhereClause sWC; /* Decomposition of the WHERE clause */
+ WhereLevel a[1]; /* Information about each nest loop in WHERE */
+};
+
+/*
+** Bitmasks for the operators on WhereTerm objects. These are all
+** operators that are of interest to the query planner. An
** OR-ed combination of these values can be used when searching for
-** terms in the where clause.
+** particular WhereTerms within a WhereClause.
*/
#define WO_IN 0x001
#define WO_EQ 0x002
@@ -233,74 +425,88 @@ struct WhereCost {
#define WO_SINGLE 0x0ff /* Mask of all non-compound WO_* values */
/*
-** Value for wsFlags returned by bestIndex() and stored in
-** WhereLevel.wsFlags. These flags determine which search
-** strategies are appropriate.
-**
-** The least significant 12 bits is reserved as a mask for WO_ values above.
-** The WhereLevel.wsFlags field is usually set to WO_IN|WO_EQ|WO_ISNULL.
-** But if the table is the right table of a left join, WhereLevel.wsFlags
-** is set to WO_IN|WO_EQ. The WhereLevel.wsFlags field can then be used as
-** the "op" parameter to findTerm when we are resolving equality constraints.
-** ISNULL constraints will then not be used on the right table of a left
-** join. Tickets #2177 and #2189.
+** These are definitions of bits in the WhereLoop.wsFlags field.
+** The particular combination of bits in each WhereLoop help to
+** determine the algorithm that WhereLoop represents.
*/
-#define WHERE_ROWID_EQ 0x00001000 /* rowid=EXPR or rowid IN (...) */
-#define WHERE_ROWID_RANGE 0x00002000 /* rowid<EXPR and/or rowid>EXPR */
-#define WHERE_COLUMN_EQ 0x00010000 /* x=EXPR or x IN (...) or x IS NULL */
-#define WHERE_COLUMN_RANGE 0x00020000 /* x<EXPR and/or x>EXPR */
-#define WHERE_COLUMN_IN 0x00040000 /* x IN (...) */
-#define WHERE_COLUMN_NULL 0x00080000 /* x IS NULL */
-#define WHERE_INDEXED 0x000f0000 /* Anything that uses an index */
-#define WHERE_NOT_FULLSCAN 0x100f3000 /* Does not do a full table scan */
-#define WHERE_IN_ABLE 0x080f1000 /* Able to support an IN operator */
-#define WHERE_TOP_LIMIT 0x00100000 /* x<EXPR or x<=EXPR constraint */
-#define WHERE_BTM_LIMIT 0x00200000 /* x>EXPR or x>=EXPR constraint */
-#define WHERE_BOTH_LIMIT 0x00300000 /* Both x>EXPR and x<EXPR */
-#define WHERE_IDX_ONLY 0x00400000 /* Use index only - omit table */
-#define WHERE_ORDERED 0x00800000 /* Output will appear in correct order */
-#define WHERE_REVERSE 0x01000000 /* Scan in reverse order */
-#define WHERE_UNIQUE 0x02000000 /* Selects no more than one row */
-#define WHERE_ALL_UNIQUE 0x04000000 /* This and all prior have one row */
-#define WHERE_OB_UNIQUE 0x00004000 /* Values in ORDER BY columns are
- ** different for every output row */
-#define WHERE_VIRTUALTABLE 0x08000000 /* Use virtual-table processing */
-#define WHERE_MULTI_OR 0x10000000 /* OR using multiple indices */
-#define WHERE_TEMP_INDEX 0x20000000 /* Uses an ephemeral index */
-#define WHERE_DISTINCT 0x40000000 /* Correct order for DISTINCT */
-#define WHERE_COVER_SCAN 0x80000000 /* Full scan of a covering index */
+#define WHERE_COLUMN_EQ 0x00000001 /* x=EXPR or x IN (...) or x IS NULL */
+#define WHERE_COLUMN_RANGE 0x00000002 /* x<EXPR and/or x>EXPR */
+#define WHERE_COLUMN_IN 0x00000004 /* x IN (...) */
+#define WHERE_COLUMN_NULL 0x00000008 /* x IS NULL */
+#define WHERE_CONSTRAINT 0x0000000f /* Any of the WHERE_COLUMN_xxx values */
+#define WHERE_TOP_LIMIT 0x00000010 /* x<EXPR or x<=EXPR constraint */
+#define WHERE_BTM_LIMIT 0x00000020 /* x>EXPR or x>=EXPR constraint */
+#define WHERE_BOTH_LIMIT 0x00000030 /* Both x>EXPR and x<EXPR */
+#define WHERE_IDX_ONLY 0x00000040 /* Use index only - omit table */
+#define WHERE_IPK 0x00000100 /* x is the INTEGER PRIMARY KEY */
+#define WHERE_INDEXED 0x00000200 /* WhereLoop.u.btree.pIndex is valid */
+#define WHERE_VIRTUALTABLE 0x00000400 /* WhereLoop.u.vtab is valid */
+#define WHERE_IN_ABLE 0x00000800 /* Able to support an IN operator */
+#define WHERE_ONEROW 0x00001000 /* Selects no more than one row */
+#define WHERE_MULTI_OR 0x00002000 /* OR using multiple indices */
+#define WHERE_TEMP_INDEX 0x00004000 /* Uses an ephemeral index */
+
+
+/* Convert a WhereCost value (10 times log2(X)) into its integer value X.
+** A rough approximation is used. The value returned is not exact.
+*/
+static u64 whereCostToInt(WhereCost x){
+ u64 n;
+ if( x<10 ) return 1;
+ n = x%10;
+ x /= 10;
+ if( n>=5 ) n -= 2;
+ else if( n>=1 ) n -= 1;
+ if( x>=3 ) return (n+8)<<(x-3);
+ return (n+8)>>(3-x);
+}
/*
-** This module contains many separate subroutines that work together to
-** find the best indices to use for accessing a particular table in a query.
-** An instance of the following structure holds context information about the
-** index search so that it can be more easily passed between the various
-** routines.
+** Return the estimated number of output rows from a WHERE clause
*/
-typedef struct WhereBestIdx WhereBestIdx;
-struct WhereBestIdx {
- Parse *pParse; /* Parser context */
- WhereClause *pWC; /* The WHERE clause */
- struct SrcList_item *pSrc; /* The FROM clause term to search */
- Bitmask notReady; /* Mask of cursors not available */
- Bitmask notValid; /* Cursors not available for any purpose */
- ExprList *pOrderBy; /* The ORDER BY clause */
- ExprList *pDistinct; /* The select-list if query is DISTINCT */
- sqlite3_index_info **ppIdxInfo; /* Index information passed to xBestIndex */
- int i, n; /* Which loop is being coded; # of loops */
- WhereLevel *aLevel; /* Info about outer loops */
- WhereCost cost; /* Lowest cost query plan */
-};
+u64 sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
+ return whereCostToInt(pWInfo->nRowOut);
+}
/*
-** Return TRUE if the probe cost is less than the baseline cost
+** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
+** WHERE clause returns outputs for DISTINCT processing.
*/
-static int compareCost(const WhereCost *pProbe, const WhereCost *pBaseline){
- if( pProbe->rCost<pBaseline->rCost ) return 1;
- if( pProbe->rCost>pBaseline->rCost ) return 0;
- if( pProbe->plan.nOBSat>pBaseline->plan.nOBSat ) return 1;
- if( pProbe->plan.nRow<pBaseline->plan.nRow ) return 1;
- return 0;
+int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
+ return pWInfo->eDistinct;
+}
+
+/*
+** Return TRUE if the WHERE clause returns rows in ORDER BY order.
+** Return FALSE if the output needs to be sorted.
+*/
+int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
+ return pWInfo->bOBSat!=0;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to continue
+** immediately with the next row of a WHERE clause.
+*/
+int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
+ return pWInfo->iContinue;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to break
+** out of a WHERE loop.
+*/
+int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
+ return pWInfo->iBreak;
+}
+
+/*
+** Return TRUE if an UPDATE or DELETE statement can operate directly on
+** the rowids returned by a WHERE clause. Return FALSE if doing an
+** UPDATE or DELETE might change subsequent WHERE clause results.
+*/
+int sqlite3WhereOkOnePass(WhereInfo *pWInfo){
+ return pWInfo->okOnePass;
}
/*
@@ -308,17 +514,13 @@ static int compareCost(const WhereCost *pProbe, const WhereCost *pBaseline){
*/
static void whereClauseInit(
WhereClause *pWC, /* The WhereClause to be initialized */
- Parse *pParse, /* The parsing context */
- WhereMaskSet *pMaskSet, /* Mapping from table cursor numbers to bitmasks */
- u16 wctrlFlags /* Might include WHERE_AND_ONLY */
+ WhereInfo *pWInfo /* The WHERE processing context */
){
- pWC->pParse = pParse;
- pWC->pMaskSet = pMaskSet;
+ pWC->pWInfo = pWInfo;
pWC->pOuter = 0;
pWC->nTerm = 0;
pWC->nSlot = ArraySize(pWC->aStatic);
pWC->a = pWC->aStatic;
- pWC->wctrlFlags = wctrlFlags;
}
/* Forward reference */
@@ -347,7 +549,7 @@ static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
static void whereClauseClear(WhereClause *pWC){
int i;
WhereTerm *a;
- sqlite3 *db = pWC->pParse->db;
+ sqlite3 *db = pWC->pWInfo->pParse->db;
for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
if( a->wtFlags & TERM_DYNAMIC ){
sqlite3ExprDelete(db, a->pExpr);
@@ -388,7 +590,7 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
testcase( wtFlags & TERM_VIRTUAL ); /* EV: R-00211-15100 */
if( pWC->nTerm>=pWC->nSlot ){
WhereTerm *pOld = pWC->a;
- sqlite3 *db = pWC->pParse->db;
+ sqlite3 *db = pWC->pWInfo->pParse->db;
pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
if( pWC->a==0 ){
if( wtFlags & TERM_DYNAMIC ){
@@ -428,8 +630,8 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
** the WhereClause.a[] array. The slot[] array grows as needed to contain
** all terms of the WHERE clause.
*/
-static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
- pWC->op = (u8)op;
+static void whereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
+ pWC->op = op;
if( pExpr==0 ) return;
if( pExpr->op!=op ){
whereClauseInsert(pWC, pExpr, 0);
@@ -440,9 +642,9 @@ static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
}
/*
-** Initialize an expression mask set (a WhereMaskSet object)
+** Initialize a WhereMaskSet object
*/
-#define initMaskSet(P) memset(P, 0, sizeof(*P))
+#define initMaskSet(P) (P)->n=0
/*
** Return the bitmask for the given cursor number. Return 0 if
@@ -453,7 +655,7 @@ static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
for(i=0; i<pMaskSet->n; i++){
if( pMaskSet->ix[i]==iCursor ){
- return ((Bitmask)1)<<i;
+ return MASKBIT(i);
}
}
return 0;
@@ -473,18 +675,9 @@ static void createMask(WhereMaskSet *pMaskSet, int iCursor){
}
/*
-** This routine walks (recursively) an expression tree and generates
+** These routine walk (recursively) an expression tree and generates
** a bitmask indicating which tables are used in that expression
** tree.
-**
-** In order for this routine to work, the calling function must have
-** previously invoked sqlite3ResolveExprNames() on the expression. See
-** the header comment on that routine for additional information.
-** The sqlite3ResolveExprNames() routines looks for column names and
-** sets their opcodes to TK_COLUMN and their Expr.iTable fields to
-** the VDBE cursor number of the table. This routine just has to
-** translate the cursor numbers into bitmask values and OR all
-** the bitmasks together.
*/
static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*);
static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*);
@@ -538,7 +731,7 @@ static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
/*
** Return TRUE if the given operator is one of the operators that is
** allowed for an indexable WHERE clause term. The allowed operators are
-** "=", "<", ">", "<=", ">=", and "IN".
+** "=", "<", ">", "<=", ">=", "IN", and "IS NULL"
**
** IMPLEMENTATION-OF: R-59926-26393 To be usable by an index a term must be
** of one of the following forms: column = expression column > expression
@@ -565,10 +758,9 @@ static int allowedOp(int op){
** are converted into "Y op X".
**
** If left/right precedence rules come into play when determining the
-** collating
-** side of the comparison, it remains associated with the same side after
-** the commutation. So "Y collate NOCASE op X" becomes
-** "X op Y". This is because any collation sequence on
+** collating sequence, then COLLATE operators are adjusted to ensure
+** that the collating sequence does not change. For example:
+** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
** the left hand side of a comparison overrides any collation sequence
** attached to the right. For the same reason the EP_Collate flag
** is not commuted.
@@ -626,6 +818,130 @@ static u16 operatorMask(int op){
}
/*
+** Advance to the next WhereTerm that matches according to the criteria
+** established when the pScan object was initialized by whereScanInit().
+** Return NULL if there are no more matching WhereTerms.
+*/
+WhereTerm *whereScanNext(WhereScan *pScan){
+ int iCur; /* The cursor on the LHS of the term */
+ int iColumn; /* The column on the LHS of the term. -1 for IPK */
+ Expr *pX; /* An expression being tested */
+ WhereClause *pWC; /* Shorthand for pScan->pWC */
+ WhereTerm *pTerm; /* The term being tested */
+ int k = pScan->k; /* Where to start scanning */
+
+ while( pScan->iEquiv<=pScan->nEquiv ){
+ iCur = pScan->aEquiv[pScan->iEquiv-2];
+ iColumn = pScan->aEquiv[pScan->iEquiv-1];
+ while( (pWC = pScan->pWC)!=0 ){
+ for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
+ if( pTerm->leftCursor==iCur && pTerm->u.leftColumn==iColumn ){
+ if( (pTerm->eOperator & WO_EQUIV)!=0
+ && pScan->nEquiv<ArraySize(pScan->aEquiv)
+ ){
+ int j;
+ pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
+ assert( pX->op==TK_COLUMN );
+ for(j=0; j<pScan->nEquiv; j+=2){
+ if( pScan->aEquiv[j]==pX->iTable
+ && pScan->aEquiv[j+1]==pX->iColumn ){
+ break;
+ }
+ }
+ if( j==pScan->nEquiv ){
+ pScan->aEquiv[j] = pX->iTable;
+ pScan->aEquiv[j+1] = pX->iColumn;
+ pScan->nEquiv += 2;
+ }
+ }
+ if( (pTerm->eOperator & pScan->opMask)!=0 ){
+ /* Verify the affinity and collating sequence match */
+ if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
+ CollSeq *pColl;
+ Parse *pParse = pWC->pWInfo->pParse;
+ pX = pTerm->pExpr;
+ if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
+ continue;
+ }
+ assert(pX->pLeft);
+ pColl = sqlite3BinaryCompareCollSeq(pParse,
+ pX->pLeft, pX->pRight);
+ if( pColl==0 ) pColl = pParse->db->pDfltColl;
+ if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
+ continue;
+ }
+ }
+ if( (pTerm->eOperator & WO_EQ)!=0
+ && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
+ && pX->iTable==pScan->aEquiv[0]
+ && pX->iColumn==pScan->aEquiv[1]
+ ){
+ continue;
+ }
+ pScan->k = k+1;
+ return pTerm;
+ }
+ }
+ }
+ pScan->pWC = pScan->pWC->pOuter;
+ k = 0;
+ }
+ pScan->pWC = pScan->pOrigWC;
+ k = 0;
+ pScan->iEquiv += 2;
+ }
+ return 0;
+}
+
+/*
+** Initialize a WHERE clause scanner object. Return a pointer to the
+** first match. Return NULL if there are no matches.
+**
+** The scanner will be searching the WHERE clause pWC. It will look
+** for terms of the form "X <op> <expr>" where X is column iColumn of table
+** iCur. The <op> must be one of the operators described by opMask.
+**
+** If the search is for X and the WHERE clause contains terms of the
+** form X=Y then this routine might also return terms of the form
+** "Y <op> <expr>". The number of levels of transitivity is limited,
+** but is enough to handle most commonly occurring SQL statements.
+**
+** If X is not the INTEGER PRIMARY KEY then X must be compatible with
+** index pIdx.
+*/
+WhereTerm *whereScanInit(
+ WhereScan *pScan, /* The WhereScan object being initialized */
+ WhereClause *pWC, /* The WHERE clause to be scanned */
+ int iCur, /* Cursor to scan for */
+ int iColumn, /* Column to scan for */
+ u32 opMask, /* Operator(s) to scan for */
+ Index *pIdx /* Must be compatible with this index */
+){
+ int j;
+
+ /* memset(pScan, 0, sizeof(*pScan)); */
+ pScan->pOrigWC = pWC;
+ pScan->pWC = pWC;
+ if( pIdx && iColumn>=0 ){
+ pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
+ for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
+ if( NEVER(j>=pIdx->nColumn) ) return 0;
+ }
+ pScan->zCollName = pIdx->azColl[j];
+ }else{
+ pScan->idxaff = 0;
+ pScan->zCollName = 0;
+ }
+ pScan->opMask = opMask;
+ pScan->k = 0;
+ pScan->aEquiv[0] = iCur;
+ pScan->aEquiv[1] = iColumn;
+ pScan->nEquiv = 2;
+ pScan->iEquiv = 2;
+ return whereScanNext(pScan);
+}
+
+/*
** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
** where X is a reference to the iColumn of table iCur and <op> is one of
** the WO_xx operator codes specified by the op parameter.
@@ -656,84 +972,20 @@ static WhereTerm *findTerm(
u32 op, /* Mask of WO_xx values describing operator */
Index *pIdx /* Must be compatible with this index, if not NULL */
){
- WhereTerm *pTerm; /* Term being examined as possible result */
- WhereTerm *pResult = 0; /* The answer to return */
- WhereClause *pWCOrig = pWC; /* Original pWC value */
- int j, k; /* Loop counters */
- Expr *pX; /* Pointer to an expression */
- Parse *pParse; /* Parsing context */
- int iOrigCol = iColumn; /* Original value of iColumn */
- int nEquiv = 2; /* Number of entires in aEquiv[] */
- int iEquiv = 2; /* Number of entries of aEquiv[] processed so far */
- int aEquiv[22]; /* iCur,iColumn and up to 10 other equivalents */
-
- assert( iCur>=0 );
- aEquiv[0] = iCur;
- aEquiv[1] = iColumn;
- for(;;){
- for(pWC=pWCOrig; pWC; pWC=pWC->pOuter){
- for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
- if( pTerm->leftCursor==iCur
- && pTerm->u.leftColumn==iColumn
- ){
- if( (pTerm->prereqRight & notReady)==0
- && (pTerm->eOperator & op & WO_ALL)!=0
- ){
- if( iOrigCol>=0 && pIdx && (pTerm->eOperator & WO_ISNULL)==0 ){
- CollSeq *pColl;
- char idxaff;
-
- pX = pTerm->pExpr;
- pParse = pWC->pParse;
- idxaff = pIdx->pTable->aCol[iOrigCol].affinity;
- if( !sqlite3IndexAffinityOk(pX, idxaff) ){
- continue;
- }
-
- /* Figure out the collation sequence required from an index for
- ** it to be useful for optimising expression pX. Store this
- ** value in variable pColl.
- */
- assert(pX->pLeft);
- pColl = sqlite3BinaryCompareCollSeq(pParse,pX->pLeft,pX->pRight);
- if( pColl==0 ) pColl = pParse->db->pDfltColl;
-
- for(j=0; pIdx->aiColumn[j]!=iOrigCol; j++){
- if( NEVER(j>=pIdx->nColumn) ) return 0;
- }
- if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ){
- continue;
- }
- }
- if( pTerm->prereqRight==0 && (pTerm->eOperator&WO_EQ)!=0 ){
- pResult = pTerm;
- goto findTerm_success;
- }else if( pResult==0 ){
- pResult = pTerm;
- }
- }
- if( (pTerm->eOperator & WO_EQUIV)!=0
- && nEquiv<ArraySize(aEquiv)
- ){
- pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
- assert( pX->op==TK_COLUMN );
- for(j=0; j<nEquiv; j+=2){
- if( aEquiv[j]==pX->iTable && aEquiv[j+1]==pX->iColumn ) break;
- }
- if( j==nEquiv ){
- aEquiv[j] = pX->iTable;
- aEquiv[j+1] = pX->iColumn;
- nEquiv += 2;
- }
- }
- }
+ WhereTerm *pResult = 0;
+ WhereTerm *p;
+ WhereScan scan;
+
+ p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
+ while( p ){
+ if( (p->prereqRight & notReady)==0 ){
+ if( p->prereqRight==0 && (p->eOperator&WO_EQ)!=0 ){
+ return p;
}
+ if( pResult==0 ) pResult = p;
}
- if( iEquiv>=nEquiv ) break;
- iCur = aEquiv[iEquiv++];
- iColumn = aEquiv[iEquiv++];
+ p = whereScanNext(&scan);
}
-findTerm_success:
return pResult;
}
@@ -742,8 +994,6 @@ static void exprAnalyze(SrcList*, WhereClause*, int);
/*
** Call exprAnalyze on all terms in a WHERE clause.
-**
-**
*/
static void exprAnalyzeAll(
SrcList *pTabList, /* the FROM clause */
@@ -975,11 +1225,11 @@ static void exprAnalyzeOrTerm(
WhereClause *pWC, /* the complete WHERE clause */
int idxTerm /* Index of the OR-term to be analyzed */
){
- Parse *pParse = pWC->pParse; /* Parser context */
+ WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
+ Parse *pParse = pWInfo->pParse; /* Parser context */
sqlite3 *db = pParse->db; /* Database connection */
WhereTerm *pTerm = &pWC->a[idxTerm]; /* The term to be analyzed */
Expr *pExpr = pTerm->pExpr; /* The expression of the term */
- WhereMaskSet *pMaskSet = pWC->pMaskSet; /* Table use masks */
int i; /* Loop counters */
WhereClause *pOrWc; /* Breakup of pTerm into subterms */
WhereTerm *pOrTerm; /* A Sub-term within the pOrWc */
@@ -998,7 +1248,7 @@ static void exprAnalyzeOrTerm(
if( pOrInfo==0 ) return;
pTerm->wtFlags |= TERM_ORINFO;
pOrWc = &pOrInfo->wc;
- whereClauseInit(pOrWc, pWC->pParse, pMaskSet, pWC->wctrlFlags);
+ whereClauseInit(pOrWc, pWInfo);
whereSplit(pOrWc, pExpr, TK_OR);
exprAnalyzeAll(pSrc, pOrWc);
if( db->mallocFailed ) return;
@@ -1024,7 +1274,7 @@ static void exprAnalyzeOrTerm(
pOrTerm->wtFlags |= TERM_ANDINFO;
pOrTerm->eOperator = WO_AND;
pAndWC = &pAndInfo->wc;
- whereClauseInit(pAndWC, pWC->pParse, pMaskSet, pWC->wctrlFlags);
+ whereClauseInit(pAndWC, pWC->pWInfo);
whereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
exprAnalyzeAll(pSrc, pAndWC);
pAndWC->pOuter = pWC;
@@ -1033,7 +1283,7 @@ static void exprAnalyzeOrTerm(
for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
assert( pAndTerm->pExpr );
if( allowedOp(pAndTerm->pExpr->op) ){
- b |= getMask(pMaskSet, pAndTerm->leftCursor);
+ b |= getMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
}
}
}
@@ -1044,10 +1294,10 @@ static void exprAnalyzeOrTerm(
** corresponding TERM_VIRTUAL term */
}else{
Bitmask b;
- b = getMask(pMaskSet, pOrTerm->leftCursor);
+ b = getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
if( pOrTerm->wtFlags & TERM_VIRTUAL ){
WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
- b |= getMask(pMaskSet, pOther->leftCursor);
+ b |= getMask(&pWInfo->sMaskSet, pOther->leftCursor);
}
indexable &= b;
if( (pOrTerm->eOperator & WO_EQ)==0 ){
@@ -1109,7 +1359,7 @@ static void exprAnalyzeOrTerm(
assert( j==1 );
continue;
}
- if( (chngToIN & getMask(pMaskSet, pOrTerm->leftCursor))==0 ){
+ if( (chngToIN & getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){
/* This term must be of the form t1.a==t2.b where t2 is in the
** chngToIN set but t1 is not. This term will be either preceeded
** or follwed by an inverted copy (t2.b==t1.a). Skip this term
@@ -1128,7 +1378,7 @@ static void exprAnalyzeOrTerm(
** on the second iteration */
assert( j==1 );
assert( IsPowerOfTwo(chngToIN) );
- assert( chngToIN==getMask(pMaskSet, iCursor) );
+ assert( chngToIN==getMask(&pWInfo->sMaskSet, iCursor) );
break;
}
testcase( j==1 );
@@ -1177,7 +1427,7 @@ static void exprAnalyzeOrTerm(
assert( pOrTerm->leftCursor==iCursor );
assert( pOrTerm->u.leftColumn==iColumn );
pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
- pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup);
+ pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
pLeft = pOrTerm->pExpr->pLeft;
}
assert( pLeft!=0 );
@@ -1226,6 +1476,7 @@ static void exprAnalyze(
WhereClause *pWC, /* the WHERE clause */
int idxTerm /* Index of the term to be analyzed */
){
+ WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
WhereTerm *pTerm; /* The term to be analyzed */
WhereMaskSet *pMaskSet; /* Set of table index masks */
Expr *pExpr; /* The expression to be analyzed */
@@ -1236,14 +1487,14 @@ static void exprAnalyze(
int isComplete = 0; /* RHS of LIKE/GLOB ends with wildcard */
int noCase = 0; /* LIKE/GLOB distinguishes case */
int op; /* Top-level operator. pExpr->op */
- Parse *pParse = pWC->pParse; /* Parsing context */
+ Parse *pParse = pWInfo->pParse; /* Parsing context */
sqlite3 *db = pParse->db; /* Database connection */
if( db->mallocFailed ){
return;
}
pTerm = &pWC->a[idxTerm];
- pMaskSet = pWC->pMaskSet;
+ pMaskSet = &pWInfo->sMaskSet;
pExpr = pTerm->pExpr;
assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
@@ -1521,11 +1772,8 @@ static void exprAnalyze(
}
/*
-** This function searches the expression list passed as the second argument
-** for an expression of type TK_COLUMN that refers to the same column and
-** uses the same collation sequence as the iCol'th column of index pIdx.
-** Argument iBase is the cursor number used for the table that pIdx refers
-** to.
+** This function searches pList for a entry that matches the iCol-th column
+** of index pIdx.
**
** If such an expression is found, its index in pList->a[] is returned. If
** no expression is found, -1 is returned.
@@ -1557,76 +1805,17 @@ static int findIndexCol(
}
/*
-** This routine determines if pIdx can be used to assist in processing a
-** DISTINCT qualifier. In other words, it tests whether or not using this
-** index for the outer loop guarantees that rows with equal values for
-** all expressions in the pDistinct list are delivered grouped together.
-**
-** For example, the query
-**
-** SELECT DISTINCT a, b, c FROM tbl WHERE a = ?
-**
-** can benefit from any index on columns "b" and "c".
-*/
-static int isDistinctIndex(
- Parse *pParse, /* Parsing context */
- WhereClause *pWC, /* The WHERE clause */
- Index *pIdx, /* The index being considered */
- int base, /* Cursor number for the table pIdx is on */
- ExprList *pDistinct, /* The DISTINCT expressions */
- int nEqCol /* Number of index columns with == */
-){
- Bitmask mask = 0; /* Mask of unaccounted for pDistinct exprs */
- int i; /* Iterator variable */
-
- assert( pDistinct!=0 );
- if( pIdx->zName==0 || pDistinct->nExpr>=BMS ) return 0;
- testcase( pDistinct->nExpr==BMS-1 );
-
- /* Loop through all the expressions in the distinct list. If any of them
- ** are not simple column references, return early. Otherwise, test if the
- ** WHERE clause contains a "col=X" clause. If it does, the expression
- ** can be ignored. If it does not, and the column does not belong to the
- ** same table as index pIdx, return early. Finally, if there is no
- ** matching "col=X" expression and the column is on the same table as pIdx,
- ** set the corresponding bit in variable mask.
- */
- for(i=0; i<pDistinct->nExpr; i++){
- WhereTerm *pTerm;
- Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
- if( p->op!=TK_COLUMN ) return 0;
- pTerm = findTerm(pWC, p->iTable, p->iColumn, ~(Bitmask)0, WO_EQ, 0);
- if( pTerm ){
- Expr *pX = pTerm->pExpr;
- CollSeq *p1 = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
- CollSeq *p2 = sqlite3ExprCollSeq(pParse, p);
- if( p1==p2 ) continue;
- }
- if( p->iTable!=base ) return 0;
- mask |= (((Bitmask)1) << i);
- }
-
- for(i=nEqCol; mask && i<pIdx->nColumn; i++){
- int iExpr = findIndexCol(pParse, pDistinct, base, pIdx, i);
- if( iExpr<0 ) break;
- mask &= ~(((Bitmask)1) << iExpr);
- }
-
- return (mask==0);
-}
-
-
-/*
** Return true if the DISTINCT expression-list passed as the third argument
-** is redundant. A DISTINCT list is redundant if the database contains a
-** UNIQUE index that guarantees that the result of the query will be distinct
-** anyway.
+** is redundant.
+**
+** A DISTINCT list is redundant if the database contains some subset of
+** columns that are unique and non-null.
*/
static int isDistinctRedundant(
- Parse *pParse,
- SrcList *pTabList,
- WhereClause *pWC,
- ExprList *pDistinct
+ Parse *pParse, /* Parsing context */
+ SrcList *pTabList, /* The FROM clause */
+ WhereClause *pWC, /* The WHERE clause */
+ ExprList *pDistinct /* The result set that needs to be DISTINCT */
){
Table *pTab;
Index *pIdx;
@@ -1682,21 +1871,76 @@ static int isDistinctRedundant(
return 0;
}
+/*
+** The (an approximate) sum of two WhereCosts. This computation is
+** not a simple "+" operator because WhereCost is stored as a logarithmic
+** value.
+**
+*/
+static WhereCost whereCostAdd(WhereCost a, WhereCost b){
+ static const unsigned char x[] = {
+ 10, 10, /* 0,1 */
+ 9, 9, /* 2,3 */
+ 8, 8, /* 4,5 */
+ 7, 7, 7, /* 6,7,8 */
+ 6, 6, 6, /* 9,10,11 */
+ 5, 5, 5, /* 12-14 */
+ 4, 4, 4, 4, /* 15-18 */
+ 3, 3, 3, 3, 3, 3, /* 19-24 */
+ 2, 2, 2, 2, 2, 2, 2, /* 25-31 */
+ };
+ if( a>=b ){
+ if( a>b+49 ) return a;
+ if( a>b+31 ) return a+1;
+ return a+x[a-b];
+ }else{
+ if( b>a+49 ) return b;
+ if( b>a+31 ) return b+1;
+ return b+x[b-a];
+ }
+}
+
+/*
+** Convert an integer into a WhereCost. In other words, compute a
+** good approximatation for 10*log2(x).
+*/
+static WhereCost whereCost(tRowcnt x){
+ static WhereCost a[] = { 0, 2, 3, 5, 6, 7, 8, 9 };
+ WhereCost y = 40;
+ if( x<8 ){
+ if( x<2 ) return 0;
+ while( x<8 ){ y -= 10; x <<= 1; }
+ }else{
+ while( x>255 ){ y += 40; x >>= 4; }
+ while( x>15 ){ y += 10; x >>= 1; }
+ }
+ return a[x&7] + y - 10;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Convert a double (as received from xBestIndex of a virtual table)
+** into a WhereCost. In other words, compute an approximation for
+** 10*log2(x).
+*/
+static WhereCost whereCostFromDouble(double x){
+ u64 a;
+ WhereCost e;
+ assert( sizeof(x)==8 && sizeof(a)==8 );
+ if( x<=1 ) return 0;
+ if( x<=2000000000 ) return whereCost((tRowcnt)x);
+ memcpy(&a, &x, 8);
+ e = (a>>52) - 1022;
+ return e*10;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
/*
-** Prepare a crude estimate of the logarithm of the input value.
-** The results need not be exact. This is only used for estimating
-** the total cost of performing operations with O(logN) or O(NlogN)
-** complexity. Because N is just a guess, it is no great tragedy if
-** logN is a little off.
+** Estimate the logarithm of the input value to base 2.
*/
-static double estLog(double N){
- double logN = 1;
- double x = 10;
- while( N>x ){
- logN += 1;
- x *= 10;
- }
- return logN;
+static WhereCost estLog(WhereCost N){
+ WhereCost x = whereCost(N);
+ return x>33 ? x - 33 : 0;
}
/*
@@ -1705,7 +1949,7 @@ static double estLog(double N){
** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
** are no-ops.
*/
-#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_DEBUG)
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
int i;
if( !sqlite3WhereTrace ) return;
@@ -1743,107 +1987,6 @@ static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
#define TRACE_IDX_OUTPUTS(A)
#endif
-/*
-** Required because bestIndex() is called by bestOrClauseIndex()
-*/
-static void bestIndex(WhereBestIdx*);
-
-/*
-** This routine attempts to find an scanning strategy that can be used
-** to optimize an 'OR' expression that is part of a WHERE clause.
-**
-** The table associated with FROM clause term pSrc may be either a
-** regular B-Tree table or a virtual table.
-*/
-static void bestOrClauseIndex(WhereBestIdx *p){
-#ifndef SQLITE_OMIT_OR_OPTIMIZATION
- WhereClause *pWC = p->pWC; /* The WHERE clause */
- struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
- const int iCur = pSrc->iCursor; /* The cursor of the table */
- const Bitmask maskSrc = getMask(pWC->pMaskSet, iCur); /* Bitmask for pSrc */
- WhereTerm * const pWCEnd = &pWC->a[pWC->nTerm]; /* End of pWC->a[] */
- WhereTerm *pTerm; /* A single term of the WHERE clause */
-
- /* The OR-clause optimization is disallowed if the INDEXED BY or
- ** NOT INDEXED clauses are used or if the WHERE_AND_ONLY bit is set. */
- if( pSrc->notIndexed || pSrc->pIndex!=0 ){
- return;
- }
- if( pWC->wctrlFlags & WHERE_AND_ONLY ){
- return;
- }
-
- /* Search the WHERE clause terms for a usable WO_OR term. */
- for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
- if( (pTerm->eOperator & WO_OR)!=0
- && ((pTerm->prereqAll & ~maskSrc) & p->notReady)==0
- && (pTerm->u.pOrInfo->indexable & maskSrc)!=0
- ){
- WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
- WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
- WhereTerm *pOrTerm;
- int flags = WHERE_MULTI_OR;
- double rTotal = 0;
- double nRow = 0;
- Bitmask used = 0;
- WhereBestIdx sBOI;
-
- sBOI = *p;
- sBOI.pOrderBy = 0;
- sBOI.pDistinct = 0;
- sBOI.ppIdxInfo = 0;
- for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
- WHERETRACE(("... Multi-index OR testing for term %d of %d....\n",
- (pOrTerm - pOrWC->a), (pTerm - pWC->a)
- ));
- if( (pOrTerm->eOperator& WO_AND)!=0 ){
- sBOI.pWC = &pOrTerm->u.pAndInfo->wc;
- bestIndex(&sBOI);
- }else if( pOrTerm->leftCursor==iCur ){
- WhereClause tempWC;
- tempWC.pParse = pWC->pParse;
- tempWC.pMaskSet = pWC->pMaskSet;
- tempWC.pOuter = pWC;
- tempWC.op = TK_AND;
- tempWC.a = pOrTerm;
- tempWC.wctrlFlags = 0;
- tempWC.nTerm = 1;
- sBOI.pWC = &tempWC;
- bestIndex(&sBOI);
- }else{
- continue;
- }
- rTotal += sBOI.cost.rCost;
- nRow += sBOI.cost.plan.nRow;
- used |= sBOI.cost.used;
- if( rTotal>=p->cost.rCost ) break;
- }
-
- /* If there is an ORDER BY clause, increase the scan cost to account
- ** for the cost of the sort. */
- if( p->pOrderBy!=0 ){
- WHERETRACE(("... sorting increases OR cost %.9g to %.9g\n",
- rTotal, rTotal+nRow*estLog(nRow)));
- rTotal += nRow*estLog(nRow);
- }
-
- /* If the cost of scanning using this OR term for optimization is
- ** less than the current cost stored in pCost, replace the contents
- ** of pCost. */
- WHERETRACE(("... multi-index OR cost=%.9g nrow=%.9g\n", rTotal, nRow));
- if( rTotal<p->cost.rCost ){
- p->cost.rCost = rTotal;
- p->cost.used = used;
- p->cost.plan.nRow = nRow;
- p->cost.plan.nOBSat = p->i ? p->aLevel[p->i-1].plan.nOBSat : 0;
- p->cost.plan.wsFlags = flags;
- p->cost.plan.u.pTerm = pTerm;
- }
- }
- }
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
-}
-
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** Return TRUE if the WHERE clause term pTerm is of a form where it
@@ -1859,88 +2002,13 @@ static int termCanDriveIndex(
if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
if( (pTerm->eOperator & WO_EQ)==0 ) return 0;
if( (pTerm->prereqRight & notReady)!=0 ) return 0;
+ if( pTerm->u.leftColumn<0 ) return 0;
aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
return 1;
}
#endif
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-/*
-** If the query plan for pSrc specified in pCost is a full table scan
-** and indexing is allows (if there is no NOT INDEXED clause) and it
-** possible to construct a transient index that would perform better
-** than a full table scan even when the cost of constructing the index
-** is taken into account, then alter the query plan to use the
-** transient index.
-*/
-static void bestAutomaticIndex(WhereBestIdx *p){
- Parse *pParse = p->pParse; /* The parsing context */
- WhereClause *pWC = p->pWC; /* The WHERE clause */
- struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
- double nTableRow; /* Rows in the input table */
- double logN; /* log(nTableRow) */
- double costTempIdx; /* per-query cost of the transient index */
- WhereTerm *pTerm; /* A single term of the WHERE clause */
- WhereTerm *pWCEnd; /* End of pWC->a[] */
- Table *pTable; /* Table tht might be indexed */
-
- if( pParse->nQueryLoop<=(double)1 ){
- /* There is no point in building an automatic index for a single scan */
- return;
- }
- if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){
- /* Automatic indices are disabled at run-time */
- return;
- }
- if( (p->cost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0
- && (p->cost.plan.wsFlags & WHERE_COVER_SCAN)==0
- ){
- /* We already have some kind of index in use for this query. */
- return;
- }
- if( pSrc->viaCoroutine ){
- /* Cannot index a co-routine */
- return;
- }
- if( pSrc->notIndexed ){
- /* The NOT INDEXED clause appears in the SQL. */
- return;
- }
- if( pSrc->isCorrelated ){
- /* The source is a correlated sub-query. No point in indexing it. */
- return;
- }
-
- assert( pParse->nQueryLoop >= (double)1 );
- pTable = pSrc->pTab;
- nTableRow = pTable->nRowEst;
- logN = estLog(nTableRow);
- costTempIdx = 2*logN*(nTableRow/pParse->nQueryLoop + 1);
- if( costTempIdx>=p->cost.rCost ){
- /* The cost of creating the transient table would be greater than
- ** doing the full table scan */
- return;
- }
-
- /* Search for any equality comparison term */
- pWCEnd = &pWC->a[pWC->nTerm];
- for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
- if( termCanDriveIndex(pTerm, pSrc, p->notReady) ){
- WHERETRACE(("auto-index reduces cost from %.1f to %.1f\n",
- p->cost.rCost, costTempIdx));
- p->cost.rCost = costTempIdx;
- p->cost.plan.nRow = logN + 1;
- p->cost.plan.wsFlags = WHERE_TEMP_INDEX;
- p->cost.used = pTerm->prereqRight;
- break;
- }
- }
-}
-#else
-# define bestAutomaticIndex(A) /* no-op */
-#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
-
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
@@ -1970,6 +2038,7 @@ static void constructAutomaticIndex(
int i; /* Loop counter */
int mxBitCol; /* Maximum column in pSrc->colUsed */
CollSeq *pColl; /* Collating sequence to on a column */
+ WhereLoop *pLoop; /* The Loop object */
Bitmask idxCols; /* Bitmap of columns used for indexing */
Bitmask extraCols; /* Bitmap of additional columns */
@@ -1984,21 +2053,25 @@ static void constructAutomaticIndex(
nColumn = 0;
pTable = pSrc->pTab;
pWCEnd = &pWC->a[pWC->nTerm];
+ pLoop = pLevel->pWLoop;
idxCols = 0;
for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
if( termCanDriveIndex(pTerm, pSrc, notReady) ){
int iCol = pTerm->u.leftColumn;
- Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol;
+ Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
testcase( iCol==BMS );
testcase( iCol==BMS-1 );
if( (idxCols & cMask)==0 ){
- nColumn++;
+ if( whereLoopResize(pParse->db, pLoop, nColumn+1) ) return;
+ pLoop->aLTerm[nColumn++] = pTerm;
idxCols |= cMask;
}
}
}
assert( nColumn>0 );
- pLevel->plan.nEq = nColumn;
+ pLoop->u.btree.nEq = pLoop->nLTerm = nColumn;
+ pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
+ | WHERE_TEMP_INDEX;
/* Count the number of additional columns needed to create a
** covering index. A "covering index" is an index that contains all
@@ -2008,17 +2081,17 @@ static void constructAutomaticIndex(
** original table changes and the index and table cannot both be used
** if they go out of sync.
*/
- extraCols = pSrc->colUsed & (~idxCols | (((Bitmask)1)<<(BMS-1)));
+ extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
mxBitCol = (pTable->nCol >= BMS-1) ? BMS-1 : pTable->nCol;
testcase( pTable->nCol==BMS-1 );
testcase( pTable->nCol==BMS-2 );
for(i=0; i<mxBitCol; i++){
- if( extraCols & (((Bitmask)1)<<i) ) nColumn++;
+ if( extraCols & MASKBIT(i) ) nColumn++;
}
- if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){
+ if( pSrc->colUsed & MASKBIT(BMS-1) ){
nColumn += pTable->nCol - BMS + 1;
}
- pLevel->plan.wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WO_EQ;
+ pLoop->wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY;
/* Construct the Index object to describe this index */
nByte = sizeof(Index);
@@ -2027,7 +2100,7 @@ static void constructAutomaticIndex(
nByte += nColumn; /* Index.aSortOrder */
pIdx = sqlite3DbMallocZero(pParse->db, nByte);
if( pIdx==0 ) return;
- pLevel->plan.u.pIdx = pIdx;
+ pLoop->u.btree.pIndex = pIdx;
pIdx->azColl = (char**)&pIdx[1];
pIdx->aiColumn = (int*)&pIdx->azColl[nColumn];
pIdx->aSortOrder = (u8*)&pIdx->aiColumn[nColumn];
@@ -2039,7 +2112,9 @@ static void constructAutomaticIndex(
for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
if( termCanDriveIndex(pTerm, pSrc, notReady) ){
int iCol = pTerm->u.leftColumn;
- Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol;
+ Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+ testcase( iCol==BMS-1 );
+ testcase( iCol==BMS );
if( (idxCols & cMask)==0 ){
Expr *pX = pTerm->pExpr;
idxCols |= cMask;
@@ -2050,18 +2125,18 @@ static void constructAutomaticIndex(
}
}
}
- assert( (u32)n==pLevel->plan.nEq );
+ assert( (u32)n==pLoop->u.btree.nEq );
/* Add additional columns needed to make the automatic index into
** a covering index */
for(i=0; i<mxBitCol; i++){
- if( extraCols & (((Bitmask)1)<<i) ){
+ if( extraCols & MASKBIT(i) ){
pIdx->aiColumn[n] = i;
pIdx->azColl[n] = "BINARY";
n++;
}
}
- if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){
+ if( pSrc->colUsed & MASKBIT(BMS-1) ){
for(i=BMS-1; i<pTable->nCol; i++){
pIdx->aiColumn[n] = i;
pIdx->azColl[n] = "BINARY";
@@ -2073,6 +2148,7 @@ static void constructAutomaticIndex(
/* Create the automatic index */
pKeyinfo = sqlite3IndexKeyinfo(pParse, pIdx);
assert( pLevel->iIdxCur>=0 );
+ pLevel->iIdxCur = pParse->nTab++;
sqlite3VdbeAddOp4(v, OP_OpenAutoindex, pLevel->iIdxCur, nColumn+1, 0,
(char*)pKeyinfo, P4_KEYINFO_HANDOFF);
VdbeComment((v, "for %s", pTable->zName));
@@ -2099,11 +2175,12 @@ static void constructAutomaticIndex(
** responsibility of the caller to eventually release the structure
** by passing the pointer returned by this function to sqlite3_free().
*/
-static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
- Parse *pParse = p->pParse;
- WhereClause *pWC = p->pWC;
- struct SrcList_item *pSrc = p->pSrc;
- ExprList *pOrderBy = p->pOrderBy;
+static sqlite3_index_info *allocateIndexInfo(
+ Parse *pParse,
+ WhereClause *pWC,
+ struct SrcList_item *pSrc,
+ ExprList *pOrderBy
+){
int i, j;
int nTerm;
struct sqlite3_index_constraint *pIdxCons;
@@ -2113,8 +2190,6 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
int nOrderBy;
sqlite3_index_info *pIdxInfo;
- WHERETRACE(("Recomputing index info for %s...\n", pSrc->pTab->zName));
-
/* Count the number of possible WHERE clause constraints referring
** to this virtual table */
for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
@@ -2150,7 +2225,6 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
+ sizeof(*pIdxOrderBy)*nOrderBy );
if( pIdxInfo==0 ){
sqlite3ErrorMsg(pParse, "out of memory");
- /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
return 0;
}
@@ -2206,8 +2280,8 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
/*
** The table object reference passed as the second argument to this function
** must represent a virtual table. This function invokes the xBestIndex()
-** method of the virtual table with the sqlite3_index_info pointer passed
-** as the argument.
+** method of the virtual table with the sqlite3_index_info object that
+** comes in as the 3rd argument to this function.
**
** If an error occurs, pParse is populated with an error message and a
** non-zero value is returned. Otherwise, 0 is returned and the output
@@ -2222,7 +2296,6 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
int i;
int rc;
- WHERETRACE(("xBestIndex for %s\n", pTab->zName));
TRACE_IDX_INPUTS(p);
rc = pVtab->pModule->xBestIndex(pVtab, p);
TRACE_IDX_OUTPUTS(p);
@@ -2248,208 +2321,9 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
return pParse->nErr;
}
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
-/*
-** Compute the best index for a virtual table.
-**
-** The best index is computed by the xBestIndex method of the virtual
-** table module. This routine is really just a wrapper that sets up
-** the sqlite3_index_info structure that is used to communicate with
-** xBestIndex.
-**
-** In a join, this routine might be called multiple times for the
-** same virtual table. The sqlite3_index_info structure is created
-** and initialized on the first invocation and reused on all subsequent
-** invocations. The sqlite3_index_info structure is also used when
-** code is generated to access the virtual table. The whereInfoDelete()
-** routine takes care of freeing the sqlite3_index_info structure after
-** everybody has finished with it.
-*/
-static void bestVirtualIndex(WhereBestIdx *p){
- Parse *pParse = p->pParse; /* The parsing context */
- WhereClause *pWC = p->pWC; /* The WHERE clause */
- struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
- Table *pTab = pSrc->pTab;
- sqlite3_index_info *pIdxInfo;
- struct sqlite3_index_constraint *pIdxCons;
- struct sqlite3_index_constraint_usage *pUsage;
- WhereTerm *pTerm;
- int i, j;
- int nOrderBy;
- int bAllowIN; /* Allow IN optimizations */
- double rCost;
-
- /* Make sure wsFlags is initialized to some sane value. Otherwise, if the
- ** malloc in allocateIndexInfo() fails and this function returns leaving
- ** wsFlags in an uninitialized state, the caller may behave unpredictably.
- */
- memset(&p->cost, 0, sizeof(p->cost));
- p->cost.plan.wsFlags = WHERE_VIRTUALTABLE;
-
- /* If the sqlite3_index_info structure has not been previously
- ** allocated and initialized, then allocate and initialize it now.
- */
- pIdxInfo = *p->ppIdxInfo;
- if( pIdxInfo==0 ){
- *p->ppIdxInfo = pIdxInfo = allocateIndexInfo(p);
- }
- if( pIdxInfo==0 ){
- return;
- }
-
- /* At this point, the sqlite3_index_info structure that pIdxInfo points
- ** to will have been initialized, either during the current invocation or
- ** during some prior invocation. Now we just have to customize the
- ** details of pIdxInfo for the current invocation and pass it to
- ** xBestIndex.
- */
-
- /* The module name must be defined. Also, by this point there must
- ** be a pointer to an sqlite3_vtab structure. Otherwise
- ** sqlite3ViewGetColumnNames() would have picked up the error.
- */
- assert( pTab->azModuleArg && pTab->azModuleArg[0] );
- assert( sqlite3GetVTable(pParse->db, pTab) );
-
- /* Try once or twice. On the first attempt, allow IN optimizations.
- ** If an IN optimization is accepted by the virtual table xBestIndex
- ** method, but the pInfo->aConstrainUsage.omit flag is not set, then
- ** the query will not work because it might allow duplicate rows in
- ** output. In that case, run the xBestIndex method a second time
- ** without the IN constraints. Usually this loop only runs once.
- ** The loop will exit using a "break" statement.
- */
- for(bAllowIN=1; 1; bAllowIN--){
- assert( bAllowIN==0 || bAllowIN==1 );
-
- /* Set the aConstraint[].usable fields and initialize all
- ** output variables to zero.
- **
- ** aConstraint[].usable is true for constraints where the right-hand
- ** side contains only references to tables to the left of the current
- ** table. In other words, if the constraint is of the form:
- **
- ** column = expr
- **
- ** and we are evaluating a join, then the constraint on column is
- ** only valid if all tables referenced in expr occur to the left
- ** of the table containing column.
- **
- ** The aConstraints[] array contains entries for all constraints
- ** on the current table. That way we only have to compute it once
- ** even though we might try to pick the best index multiple times.
- ** For each attempt at picking an index, the order of tables in the
- ** join might be different so we have to recompute the usable flag
- ** each time.
- */
- pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
- pUsage = pIdxInfo->aConstraintUsage;
- for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
- j = pIdxCons->iTermOffset;
- pTerm = &pWC->a[j];
- if( (pTerm->prereqRight&p->notReady)==0
- && (bAllowIN || (pTerm->eOperator & WO_IN)==0)
- ){
- pIdxCons->usable = 1;
- }else{
- pIdxCons->usable = 0;
- }
- }
- memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
- if( pIdxInfo->needToFreeIdxStr ){
- sqlite3_free(pIdxInfo->idxStr);
- }
- pIdxInfo->idxStr = 0;
- pIdxInfo->idxNum = 0;
- pIdxInfo->needToFreeIdxStr = 0;
- pIdxInfo->orderByConsumed = 0;
- /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */
- pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2);
- nOrderBy = pIdxInfo->nOrderBy;
- if( !p->pOrderBy ){
- pIdxInfo->nOrderBy = 0;
- }
-
- if( vtabBestIndex(pParse, pTab, pIdxInfo) ){
- return;
- }
-
- pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
- for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
- if( pUsage[i].argvIndex>0 ){
- j = pIdxCons->iTermOffset;
- pTerm = &pWC->a[j];
- p->cost.used |= pTerm->prereqRight;
- if( (pTerm->eOperator & WO_IN)!=0 ){
- if( pUsage[i].omit==0 ){
- /* Do not attempt to use an IN constraint if the virtual table
- ** says that the equivalent EQ constraint cannot be safely omitted.
- ** If we do attempt to use such a constraint, some rows might be
- ** repeated in the output. */
- break;
- }
- /* A virtual table that is constrained by an IN clause may not
- ** consume the ORDER BY clause because (1) the order of IN terms
- ** is not necessarily related to the order of output terms and
- ** (2) Multiple outputs from a single IN value will not merge
- ** together. */
- pIdxInfo->orderByConsumed = 0;
- }
- }
- }
- if( i>=pIdxInfo->nConstraint ) break;
- }
-
- /* The orderByConsumed signal is only valid if all outer loops collectively
- ** generate just a single row of output.
- */
- if( pIdxInfo->orderByConsumed ){
- for(i=0; i<p->i; i++){
- if( (p->aLevel[i].plan.wsFlags & WHERE_UNIQUE)==0 ){
- pIdxInfo->orderByConsumed = 0;
- }
- }
- }
-
- /* If there is an ORDER BY clause, and the selected virtual table index
- ** does not satisfy it, increase the cost of the scan accordingly. This
- ** matches the processing for non-virtual tables in bestBtreeIndex().
- */
- rCost = pIdxInfo->estimatedCost;
- if( p->pOrderBy && pIdxInfo->orderByConsumed==0 ){
- rCost += estLog(rCost)*rCost;
- }
-
- /* The cost is not allowed to be larger than SQLITE_BIG_DBL (the
- ** inital value of lowestCost in this loop. If it is, then the
- ** (cost<lowestCost) test below will never be true.
- **
- ** Use "(double)2" instead of "2.0" in case OMIT_FLOATING_POINT
- ** is defined.
- */
- if( (SQLITE_BIG_DBL/((double)2))<rCost ){
- p->cost.rCost = (SQLITE_BIG_DBL/((double)2));
- }else{
- p->cost.rCost = rCost;
- }
- p->cost.plan.u.pVtabIdx = pIdxInfo;
- if( pIdxInfo->orderByConsumed ){
- p->cost.plan.wsFlags |= WHERE_ORDERED;
- p->cost.plan.nOBSat = nOrderBy;
- }else{
- p->cost.plan.nOBSat = p->i ? p->aLevel[p->i-1].plan.nOBSat : 0;
- }
- p->cost.plan.nEq = 0;
- pIdxInfo->nOrderBy = nOrderBy;
-
- /* Try to find a more efficient access pattern by using multiple indexes
- ** to optimize an OR expression within the WHERE clause.
- */
- bestOrClauseIndex(p);
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
#ifdef SQLITE_ENABLE_STAT3
/*
** Estimate the location of a particular key among all keys in an
@@ -2535,9 +2409,10 @@ static int whereKeyStats(
assert( pColl->enc==SQLITE_UTF8 );
}else{
pColl = sqlite3GetCollSeq(pParse, SQLITE_UTF8, 0, *pIdx->azColl);
- if( pColl==0 ){
- return SQLITE_ERROR;
- }
+ /* If the collating sequence was unavailable, we should have failed
+ ** long ago and never reached this point. But we'll check just to
+ ** be doubly sure. */
+ if( NEVER(pColl==0) ) return SQLITE_ERROR;
z = (const u8 *)sqlite3ValueText(pVal, pColl->enc);
if( !z ){
return SQLITE_NOMEM;
@@ -2690,7 +2565,7 @@ static int whereRangeScanEst(
int nEq, /* index into p->aCol[] of the range-compared column */
WhereTerm *pLower, /* Lower bound on the range. ex: "x>123" Might be NULL */
WhereTerm *pUpper, /* Upper bound on the range. ex: "x<455" Might be NULL */
- double *pRangeDiv /* OUT: Reduce search space by this divisor */
+ WhereCost *pRangeDiv /* OUT: Reduce search space by this divisor */
){
int rc = SQLITE_OK;
@@ -2728,13 +2603,13 @@ static int whereRangeScanEst(
sqlite3ValueFree(pRangeVal);
}
if( rc==SQLITE_OK ){
- if( iUpper<=iLower ){
- *pRangeDiv = (double)p->aiRowEst[0];
- }else{
- *pRangeDiv = (double)p->aiRowEst[0]/(double)(iUpper - iLower);
+ WhereCost iBase = whereCost(p->aiRowEst[0]);
+ if( iUpper>iLower ){
+ iBase -= whereCost(iUpper - iLower);
}
- WHERETRACE(("range scan regions: %u..%u div=%g\n",
- (u32)iLower, (u32)iUpper, *pRangeDiv));
+ *pRangeDiv = iBase;
+ WHERETRACE(0x100, ("range scan regions: %u..%u div=%d\n",
+ (u32)iLower, (u32)iUpper, *pRangeDiv));
return SQLITE_OK;
}
}
@@ -2744,9 +2619,15 @@ static int whereRangeScanEst(
UNUSED_PARAMETER(nEq);
#endif
assert( pLower || pUpper );
- *pRangeDiv = (double)1;
- if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ) *pRangeDiv *= (double)4;
- if( pUpper ) *pRangeDiv *= (double)4;
+ *pRangeDiv = 0;
+ /* TUNING: Each inequality constraint reduces the search space 4-fold.
+ ** A BETWEEN operator, therefore, reduces the search space 16-fold */
+ if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ){
+ *pRangeDiv += 20; assert( 20==whereCost(4) );
+ }
+ if( pUpper ){
+ *pRangeDiv += 20; assert( 20==whereCost(4) );
+ }
return rc;
}
@@ -2772,7 +2653,7 @@ static int whereEqualScanEst(
Parse *pParse, /* Parsing & code generating context */
Index *p, /* The index whose left-most column is pTerm */
Expr *pExpr, /* Expression for VALUE in the x=VALUE constraint */
- double *pnRow /* Write the revised row estimate here */
+ tRowcnt *pnRow /* Write the revised row estimate here */
){
sqlite3_value *pRhs = 0; /* VALUE on right-hand side of pTerm */
u8 aff; /* Column affinity */
@@ -2791,7 +2672,7 @@ static int whereEqualScanEst(
if( pRhs==0 ) return SQLITE_NOTFOUND;
rc = whereKeyStats(pParse, p, pRhs, 0, a);
if( rc==SQLITE_OK ){
- WHERETRACE(("equality scan regions: %d\n", (int)a[1]));
+ WHERETRACE(0x100,("equality scan regions: %d\n", (int)a[1]));
*pnRow = a[1];
}
whereEqualScanEst_cancel:
@@ -2821,12 +2702,12 @@ static int whereInScanEst(
Parse *pParse, /* Parsing & code generating context */
Index *p, /* The index whose left-most column is pTerm */
ExprList *pList, /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
- double *pnRow /* Write the revised row estimate here */
+ tRowcnt *pnRow /* Write the revised row estimate here */
){
- int rc = SQLITE_OK; /* Subfunction return code */
- double nEst; /* Number of rows for a single term */
- double nRowEst = (double)0; /* New estimate of the number of rows */
- int i; /* Loop counter */
+ int rc = SQLITE_OK; /* Subfunction return code */
+ tRowcnt nEst; /* Number of rows for a single term */
+ tRowcnt nRowEst = 0; /* New estimate of the number of rows */
+ int i; /* Loop counter */
assert( p->aSample!=0 );
for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
@@ -2837,886 +2718,13 @@ static int whereInScanEst(
if( rc==SQLITE_OK ){
if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
*pnRow = nRowEst;
- WHERETRACE(("IN row estimate: est=%g\n", nRowEst));
+ WHERETRACE(0x100,("IN row estimate: est=%g\n", nRowEst));
}
return rc;
}
#endif /* defined(SQLITE_ENABLE_STAT3) */
/*
-** Check to see if column iCol of the table with cursor iTab will appear
-** in sorted order according to the current query plan.
-**
-** Return values:
-**
-** 0 iCol is not ordered
-** 1 iCol has only a single value
-** 2 iCol is in ASC order
-** 3 iCol is in DESC order
-*/
-static int isOrderedColumn(
- WhereBestIdx *p,
- int iTab,
- int iCol
-){
- int i, j;
- WhereLevel *pLevel = &p->aLevel[p->i-1];
- Index *pIdx;
- u8 sortOrder;
- for(i=p->i-1; i>=0; i--, pLevel--){
- if( pLevel->iTabCur!=iTab ) continue;
- if( (pLevel->plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
- return 1;
- }
- assert( (pLevel->plan.wsFlags & WHERE_ORDERED)!=0 );
- if( (pIdx = pLevel->plan.u.pIdx)!=0 ){
- if( iCol<0 ){
- sortOrder = 0;
- testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 );
- }else{
- int n = pIdx->nColumn;
- for(j=0; j<n; j++){
- if( iCol==pIdx->aiColumn[j] ) break;
- }
- if( j>=n ) return 0;
- sortOrder = pIdx->aSortOrder[j];
- testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 );
- }
- }else{
- if( iCol!=(-1) ) return 0;
- sortOrder = 0;
- testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 );
- }
- if( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 ){
- assert( sortOrder==0 || sortOrder==1 );
- testcase( sortOrder==1 );
- sortOrder = 1 - sortOrder;
- }
- return sortOrder+2;
- }
- return 0;
-}
-
-/*
-** This routine decides if pIdx can be used to satisfy the ORDER BY
-** clause, either in whole or in part. The return value is the
-** cumulative number of terms in the ORDER BY clause that are satisfied
-** by the index pIdx and other indices in outer loops.
-**
-** The table being queried has a cursor number of "base". pIdx is the
-** index that is postulated for use to access the table.
-**
-** The *pbRev value is set to 0 order 1 depending on whether or not
-** pIdx should be run in the forward order or in reverse order.
-*/
-static int isSortingIndex(
- WhereBestIdx *p, /* Best index search context */
- Index *pIdx, /* The index we are testing */
- int base, /* Cursor number for the table to be sorted */
- int *pbRev, /* Set to 1 for reverse-order scan of pIdx */
- int *pbObUnique /* ORDER BY column values will different in every row */
-){
- int i; /* Number of pIdx terms used */
- int j; /* Number of ORDER BY terms satisfied */
- int sortOrder = 2; /* 0: forward. 1: backward. 2: unknown */
- int nTerm; /* Number of ORDER BY terms */
- struct ExprList_item *pOBItem;/* A term of the ORDER BY clause */
- Table *pTab = pIdx->pTable; /* Table that owns index pIdx */
- ExprList *pOrderBy; /* The ORDER BY clause */
- Parse *pParse = p->pParse; /* Parser context */
- sqlite3 *db = pParse->db; /* Database connection */
- int nPriorSat; /* ORDER BY terms satisfied by outer loops */
- int seenRowid = 0; /* True if an ORDER BY rowid term is seen */
- int uniqueNotNull; /* pIdx is UNIQUE with all terms are NOT NULL */
- int outerObUnique; /* Outer loops generate different values in
- ** every row for the ORDER BY columns */
-
- if( p->i==0 ){
- nPriorSat = 0;
- outerObUnique = 1;
- }else{
- u32 wsFlags = p->aLevel[p->i-1].plan.wsFlags;
- nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
- if( (wsFlags & WHERE_ORDERED)==0 ){
- /* This loop cannot be ordered unless the next outer loop is
- ** also ordered */
- return nPriorSat;
- }
- if( OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ){
- /* Only look at the outer-most loop if the OrderByIdxJoin
- ** optimization is disabled */
- return nPriorSat;
- }
- testcase( wsFlags & WHERE_OB_UNIQUE );
- testcase( wsFlags & WHERE_ALL_UNIQUE );
- outerObUnique = (wsFlags & (WHERE_OB_UNIQUE|WHERE_ALL_UNIQUE))!=0;
- }
- pOrderBy = p->pOrderBy;
- assert( pOrderBy!=0 );
- if( pIdx->bUnordered ){
- /* Hash indices (indicated by the "unordered" tag on sqlite_stat1) cannot
- ** be used for sorting */
- return nPriorSat;
- }
- nTerm = pOrderBy->nExpr;
- uniqueNotNull = pIdx->onError!=OE_None;
- assert( nTerm>0 );
-
- /* Argument pIdx must either point to a 'real' named index structure,
- ** or an index structure allocated on the stack by bestBtreeIndex() to
- ** represent the rowid index that is part of every table. */
- assert( pIdx->zName || (pIdx->nColumn==1 && pIdx->aiColumn[0]==-1) );
-
- /* Match terms of the ORDER BY clause against columns of
- ** the index.
- **
- ** Note that indices have pIdx->nColumn regular columns plus
- ** one additional column containing the rowid. The rowid column
- ** of the index is also allowed to match against the ORDER BY
- ** clause.
- */
- j = nPriorSat;
- for(i=0,pOBItem=&pOrderBy->a[j]; j<nTerm && i<=pIdx->nColumn; i++){
- Expr *pOBExpr; /* The expression of the ORDER BY pOBItem */
- CollSeq *pColl; /* The collating sequence of pOBExpr */
- int termSortOrder; /* Sort order for this term */
- int iColumn; /* The i-th column of the index. -1 for rowid */
- int iSortOrder; /* 1 for DESC, 0 for ASC on the i-th index term */
- int isEq; /* Subject to an == or IS NULL constraint */
- int isMatch; /* ORDER BY term matches the index term */
- const char *zColl; /* Name of collating sequence for i-th index term */
- WhereTerm *pConstraint; /* A constraint in the WHERE clause */
-
- /* If the next term of the ORDER BY clause refers to anything other than
- ** a column in the "base" table, then this index will not be of any
- ** further use in handling the ORDER BY. */
- pOBExpr = sqlite3ExprSkipCollate(pOBItem->pExpr);
- if( pOBExpr->op!=TK_COLUMN || pOBExpr->iTable!=base ){
- break;
- }
-
- /* Find column number and collating sequence for the next entry
- ** in the index */
- if( pIdx->zName && i<pIdx->nColumn ){
- iColumn = pIdx->aiColumn[i];
- if( iColumn==pIdx->pTable->iPKey ){
- iColumn = -1;
- }
- iSortOrder = pIdx->aSortOrder[i];
- zColl = pIdx->azColl[i];
- assert( zColl!=0 );
- }else{
- iColumn = -1;
- iSortOrder = 0;
- zColl = 0;
- }
-
- /* Check to see if the column number and collating sequence of the
- ** index match the column number and collating sequence of the ORDER BY
- ** clause entry. Set isMatch to 1 if they both match. */
- if( pOBExpr->iColumn==iColumn ){
- if( zColl ){
- pColl = sqlite3ExprCollSeq(pParse, pOBItem->pExpr);
- if( !pColl ) pColl = db->pDfltColl;
- isMatch = sqlite3StrICmp(pColl->zName, zColl)==0;
- }else{
- isMatch = 1;
- }
- }else{
- isMatch = 0;
- }
-
- /* termSortOrder is 0 or 1 for whether or not the access loop should
- ** run forward or backwards (respectively) in order to satisfy this
- ** term of the ORDER BY clause. */
- assert( pOBItem->sortOrder==0 || pOBItem->sortOrder==1 );
- assert( iSortOrder==0 || iSortOrder==1 );
- termSortOrder = iSortOrder ^ pOBItem->sortOrder;
-
- /* If X is the column in the index and ORDER BY clause, check to see
- ** if there are any X= or X IS NULL constraints in the WHERE clause. */
- pConstraint = findTerm(p->pWC, base, iColumn, p->notReady,
- WO_EQ|WO_ISNULL|WO_IN, pIdx);
- if( pConstraint==0 ){
- isEq = 0;
- }else if( (pConstraint->eOperator & WO_IN)!=0 ){
- isEq = 0;
- }else if( (pConstraint->eOperator & WO_ISNULL)!=0 ){
- uniqueNotNull = 0;
- isEq = 1; /* "X IS NULL" means X has only a single value */
- }else if( pConstraint->prereqRight==0 ){
- isEq = 1; /* Constraint "X=constant" means X has only a single value */
- }else{
- Expr *pRight = pConstraint->pExpr->pRight;
- if( pRight->op==TK_COLUMN ){
- WHERETRACE((" .. isOrderedColumn(tab=%d,col=%d)",
- pRight->iTable, pRight->iColumn));
- isEq = isOrderedColumn(p, pRight->iTable, pRight->iColumn);
- WHERETRACE((" -> isEq=%d\n", isEq));
-
- /* If the constraint is of the form X=Y where Y is an ordered value
- ** in an outer loop, then make sure the sort order of Y matches the
- ** sort order required for X. */
- if( isMatch && isEq>=2 && isEq!=pOBItem->sortOrder+2 ){
- testcase( isEq==2 );
- testcase( isEq==3 );
- break;
- }
- }else{
- isEq = 0; /* "X=expr" places no ordering constraints on X */
- }
- }
- if( !isMatch ){
- if( isEq==0 ){
- break;
- }else{
- continue;
- }
- }else if( isEq!=1 ){
- if( sortOrder==2 ){
- sortOrder = termSortOrder;
- }else if( termSortOrder!=sortOrder ){
- break;
- }
- }
- j++;
- pOBItem++;
- if( iColumn<0 ){
- seenRowid = 1;
- break;
- }else if( pTab->aCol[iColumn].notNull==0 && isEq!=1 ){
- testcase( isEq==0 );
- testcase( isEq==2 );
- testcase( isEq==3 );
- uniqueNotNull = 0;
- }
- }
- if( seenRowid ){
- uniqueNotNull = 1;
- }else if( uniqueNotNull==0 || i<pIdx->nColumn ){
- uniqueNotNull = 0;
- }
-
- /* If we have not found at least one ORDER BY term that matches the
- ** index, then show no progress. */
- if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat;
-
- /* Either the outer queries must generate rows where there are no two
- ** rows with the same values in all ORDER BY columns, or else this
- ** loop must generate just a single row of output. Example: Suppose
- ** the outer loops generate A=1 and A=1, and this loop generates B=3
- ** and B=4. Then without the following test, ORDER BY A,B would
- ** generate the wrong order output: 1,3 1,4 1,3 1,4
- */
- if( outerObUnique==0 && uniqueNotNull==0 ) return nPriorSat;
- *pbObUnique = uniqueNotNull;
-
- /* Return the necessary scan order back to the caller */
- *pbRev = sortOrder & 1;
-
- /* If there was an "ORDER BY rowid" term that matched, or it is only
- ** possible for a single row from this table to match, then skip over
- ** any additional ORDER BY terms dealing with this table.
- */
- if( uniqueNotNull ){
- /* Advance j over additional ORDER BY terms associated with base */
- WhereMaskSet *pMS = p->pWC->pMaskSet;
- Bitmask m = ~getMask(pMS, base);
- while( j<nTerm && (exprTableUsage(pMS, pOrderBy->a[j].pExpr)&m)==0 ){
- j++;
- }
- }
- return j;
-}
-
-/*
-** Find the best query plan for accessing a particular table. Write the
-** best query plan and its cost into the p->cost.
-**
-** The lowest cost plan wins. The cost is an estimate of the amount of
-** CPU and disk I/O needed to process the requested result.
-** Factors that influence cost include:
-**
-** * The estimated number of rows that will be retrieved. (The
-** fewer the better.)
-**
-** * Whether or not sorting must occur.
-**
-** * Whether or not there must be separate lookups in the
-** index and in the main table.
-**
-** If there was an INDEXED BY clause (pSrc->pIndex) attached to the table in
-** the SQL statement, then this function only considers plans using the
-** named index. If no such plan is found, then the returned cost is
-** SQLITE_BIG_DBL. If a plan is found that uses the named index,
-** then the cost is calculated in the usual way.
-**
-** If a NOT INDEXED clause was attached to the table
-** in the SELECT statement, then no indexes are considered. However, the
-** selected plan may still take advantage of the built-in rowid primary key
-** index.
-*/
-static void bestBtreeIndex(WhereBestIdx *p){
- Parse *pParse = p->pParse; /* The parsing context */
- WhereClause *pWC = p->pWC; /* The WHERE clause */
- struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
- int iCur = pSrc->iCursor; /* The cursor of the table to be accessed */
- Index *pProbe; /* An index we are evaluating */
- Index *pIdx; /* Copy of pProbe, or zero for IPK index */
- int eqTermMask; /* Current mask of valid equality operators */
- int idxEqTermMask; /* Index mask of valid equality operators */
- Index sPk; /* A fake index object for the primary key */
- tRowcnt aiRowEstPk[2]; /* The aiRowEst[] value for the sPk index */
- int aiColumnPk = -1; /* The aColumn[] value for the sPk index */
- int wsFlagMask; /* Allowed flags in p->cost.plan.wsFlag */
- int nPriorSat; /* ORDER BY terms satisfied by outer loops */
- int nOrderBy; /* Number of ORDER BY terms */
- char bSortInit; /* Initializer for bSort in inner loop */
- char bDistInit; /* Initializer for bDist in inner loop */
-
-
- /* Initialize the cost to a worst-case value */
- memset(&p->cost, 0, sizeof(p->cost));
- p->cost.rCost = SQLITE_BIG_DBL;
-
- /* If the pSrc table is the right table of a LEFT JOIN then we may not
- ** use an index to satisfy IS NULL constraints on that table. This is
- ** because columns might end up being NULL if the table does not match -
- ** a circumstance which the index cannot help us discover. Ticket #2177.
- */
- if( pSrc->jointype & JT_LEFT ){
- idxEqTermMask = WO_EQ|WO_IN;
- }else{
- idxEqTermMask = WO_EQ|WO_IN|WO_ISNULL;
- }
-
- if( pSrc->pIndex ){
- /* An INDEXED BY clause specifies a particular index to use */
- pIdx = pProbe = pSrc->pIndex;
- wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE);
- eqTermMask = idxEqTermMask;
- }else{
- /* There is no INDEXED BY clause. Create a fake Index object in local
- ** variable sPk to represent the rowid primary key index. Make this
- ** fake index the first in a chain of Index objects with all of the real
- ** indices to follow */
- Index *pFirst; /* First of real indices on the table */
- memset(&sPk, 0, sizeof(Index));
- sPk.nColumn = 1;
- sPk.aiColumn = &aiColumnPk;
- sPk.aiRowEst = aiRowEstPk;
- sPk.onError = OE_Replace;
- sPk.pTable = pSrc->pTab;
- aiRowEstPk[0] = pSrc->pTab->nRowEst;
- aiRowEstPk[1] = 1;
- pFirst = pSrc->pTab->pIndex;
- if( pSrc->notIndexed==0 ){
- /* The real indices of the table are only considered if the
- ** NOT INDEXED qualifier is omitted from the FROM clause */
- sPk.pNext = pFirst;
- }
- pProbe = &sPk;
- wsFlagMask = ~(
- WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE
- );
- eqTermMask = WO_EQ|WO_IN;
- pIdx = 0;
- }
-
- nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0;
- if( p->i ){
- nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
- bSortInit = nPriorSat<nOrderBy;
- bDistInit = 0;
- }else{
- nPriorSat = 0;
- bSortInit = nOrderBy>0;
- bDistInit = p->pDistinct!=0;
- }
-
- /* Loop over all indices looking for the best one to use
- */
- for(; pProbe; pIdx=pProbe=pProbe->pNext){
- const tRowcnt * const aiRowEst = pProbe->aiRowEst;
- WhereCost pc; /* Cost of using pProbe */
- double log10N = (double)1; /* base-10 logarithm of nRow (inexact) */
-
- /* The following variables are populated based on the properties of
- ** index being evaluated. They are then used to determine the expected
- ** cost and number of rows returned.
- **
- ** pc.plan.nEq:
- ** Number of equality terms that can be implemented using the index.
- ** In other words, the number of initial fields in the index that
- ** are used in == or IN or NOT NULL constraints of the WHERE clause.
- **
- ** nInMul:
- ** The "in-multiplier". This is an estimate of how many seek operations
- ** SQLite must perform on the index in question. For example, if the
- ** WHERE clause is:
- **
- ** WHERE a IN (1, 2, 3) AND b IN (4, 5, 6)
- **
- ** SQLite must perform 9 lookups on an index on (a, b), so nInMul is
- ** set to 9. Given the same schema and either of the following WHERE
- ** clauses:
- **
- ** WHERE a = 1
- ** WHERE a >= 2
- **
- ** nInMul is set to 1.
- **
- ** If there exists a WHERE term of the form "x IN (SELECT ...)", then
- ** the sub-select is assumed to return 25 rows for the purposes of
- ** determining nInMul.
- **
- ** bInEst:
- ** Set to true if there was at least one "x IN (SELECT ...)" term used
- ** in determining the value of nInMul. Note that the RHS of the
- ** IN operator must be a SELECT, not a value list, for this variable
- ** to be true.
- **
- ** rangeDiv:
- ** An estimate of a divisor by which to reduce the search space due
- ** to inequality constraints. In the absence of sqlite_stat3 ANALYZE
- ** data, a single inequality reduces the search space to 1/4rd its
- ** original size (rangeDiv==4). Two inequalities reduce the search
- ** space to 1/16th of its original size (rangeDiv==16).
- **
- ** bSort:
- ** Boolean. True if there is an ORDER BY clause that will require an
- ** external sort (i.e. scanning the index being evaluated will not
- ** correctly order records).
- **
- ** bDist:
- ** Boolean. True if there is a DISTINCT clause that will require an
- ** external btree.
- **
- ** bLookup:
- ** Boolean. True if a table lookup is required for each index entry
- ** visited. In other words, true if this is not a covering index.
- ** This is always false for the rowid primary key index of a table.
- ** For other indexes, it is true unless all the columns of the table
- ** used by the SELECT statement are present in the index (such an
- ** index is sometimes described as a covering index).
- ** For example, given the index on (a, b), the second of the following
- ** two queries requires table b-tree lookups in order to find the value
- ** of column c, but the first does not because columns a and b are
- ** both available in the index.
- **
- ** SELECT a, b FROM tbl WHERE a = 1;
- ** SELECT a, b, c FROM tbl WHERE a = 1;
- */
- int bInEst = 0; /* True if "x IN (SELECT...)" seen */
- int nInMul = 1; /* Number of distinct equalities to lookup */
- double rangeDiv = (double)1; /* Estimated reduction in search space */
- int nBound = 0; /* Number of range constraints seen */
- char bSort = bSortInit; /* True if external sort required */
- char bDist = bDistInit; /* True if index cannot help with DISTINCT */
- char bLookup = 0; /* True if not a covering index */
- WhereTerm *pTerm; /* A single term of the WHERE clause */
-#ifdef SQLITE_ENABLE_STAT3
- WhereTerm *pFirstTerm = 0; /* First term matching the index */
-#endif
-
- WHERETRACE((
- " %s(%s):\n",
- pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk")
- ));
- memset(&pc, 0, sizeof(pc));
- pc.plan.nOBSat = nPriorSat;
-
- /* Determine the values of pc.plan.nEq and nInMul */
- for(pc.plan.nEq=0; pc.plan.nEq<pProbe->nColumn; pc.plan.nEq++){
- int j = pProbe->aiColumn[pc.plan.nEq];
- pTerm = findTerm(pWC, iCur, j, p->notReady, eqTermMask, pIdx);
- if( pTerm==0 ) break;
- pc.plan.wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ);
- testcase( pTerm->pWC!=pWC );
- if( pTerm->eOperator & WO_IN ){
- Expr *pExpr = pTerm->pExpr;
- pc.plan.wsFlags |= WHERE_COLUMN_IN;
- if( ExprHasProperty(pExpr, EP_xIsSelect) ){
- /* "x IN (SELECT ...)": Assume the SELECT returns 25 rows */
- nInMul *= 25;
- bInEst = 1;
- }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
- /* "x IN (value, value, ...)" */
- nInMul *= pExpr->x.pList->nExpr;
- }
- }else if( pTerm->eOperator & WO_ISNULL ){
- pc.plan.wsFlags |= WHERE_COLUMN_NULL;
- }
-#ifdef SQLITE_ENABLE_STAT3
- if( pc.plan.nEq==0 && pProbe->aSample ) pFirstTerm = pTerm;
-#endif
- pc.used |= pTerm->prereqRight;
- }
-
- /* If the index being considered is UNIQUE, and there is an equality
- ** constraint for all columns in the index, then this search will find
- ** at most a single row. In this case set the WHERE_UNIQUE flag to
- ** indicate this to the caller.
- **
- ** Otherwise, if the search may find more than one row, test to see if
- ** there is a range constraint on indexed column (pc.plan.nEq+1) that
- ** can be optimized using the index.
- */
- if( pc.plan.nEq==pProbe->nColumn && pProbe->onError!=OE_None ){
- testcase( pc.plan.wsFlags & WHERE_COLUMN_IN );
- testcase( pc.plan.wsFlags & WHERE_COLUMN_NULL );
- if( (pc.plan.wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
- pc.plan.wsFlags |= WHERE_UNIQUE;
- if( p->i==0 || (p->aLevel[p->i-1].plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
- pc.plan.wsFlags |= WHERE_ALL_UNIQUE;
- }
- }
- }else if( pProbe->bUnordered==0 ){
- int j;
- j = (pc.plan.nEq==pProbe->nColumn ? -1 : pProbe->aiColumn[pc.plan.nEq]);
- if( findTerm(pWC, iCur, j, p->notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){
- WhereTerm *pTop, *pBtm;
- pTop = findTerm(pWC, iCur, j, p->notReady, WO_LT|WO_LE, pIdx);
- pBtm = findTerm(pWC, iCur, j, p->notReady, WO_GT|WO_GE, pIdx);
- whereRangeScanEst(pParse, pProbe, pc.plan.nEq, pBtm, pTop, &rangeDiv);
- if( pTop ){
- nBound = 1;
- pc.plan.wsFlags |= WHERE_TOP_LIMIT;
- pc.used |= pTop->prereqRight;
- testcase( pTop->pWC!=pWC );
- }
- if( pBtm ){
- nBound++;
- pc.plan.wsFlags |= WHERE_BTM_LIMIT;
- pc.used |= pBtm->prereqRight;
- testcase( pBtm->pWC!=pWC );
- }
- pc.plan.wsFlags |= (WHERE_COLUMN_RANGE|WHERE_ROWID_RANGE);
- }
- }
-
- /* If there is an ORDER BY clause and the index being considered will
- ** naturally scan rows in the required order, set the appropriate flags
- ** in pc.plan.wsFlags. Otherwise, if there is an ORDER BY clause but
- ** the index will scan rows in a different order, set the bSort
- ** variable. */
- if( bSort && (pSrc->jointype & JT_LEFT)==0 ){
- int bRev = 2;
- int bObUnique = 0;
- WHERETRACE((" --> before isSortIndex: nPriorSat=%d\n",nPriorSat));
- pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev, &bObUnique);
- WHERETRACE((" --> after isSortIndex: bRev=%d bObU=%d nOBSat=%d\n",
- bRev, bObUnique, pc.plan.nOBSat));
- if( nPriorSat<pc.plan.nOBSat || (pc.plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
- pc.plan.wsFlags |= WHERE_ORDERED;
- if( bObUnique ) pc.plan.wsFlags |= WHERE_OB_UNIQUE;
- }
- if( nOrderBy==pc.plan.nOBSat ){
- bSort = 0;
- pc.plan.wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE;
- }
- if( bRev & 1 ) pc.plan.wsFlags |= WHERE_REVERSE;
- }
-
- /* If there is a DISTINCT qualifier and this index will scan rows in
- ** order of the DISTINCT expressions, clear bDist and set the appropriate
- ** flags in pc.plan.wsFlags. */
- if( bDist
- && isDistinctIndex(pParse, pWC, pProbe, iCur, p->pDistinct, pc.plan.nEq)
- && (pc.plan.wsFlags & WHERE_COLUMN_IN)==0
- ){
- bDist = 0;
- pc.plan.wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT;
- }
-
- /* If currently calculating the cost of using an index (not the IPK
- ** index), determine if all required column data may be obtained without
- ** using the main table (i.e. if the index is a covering
- ** index for this query). If it is, set the WHERE_IDX_ONLY flag in
- ** pc.plan.wsFlags. Otherwise, set the bLookup variable to true. */
- if( pIdx ){
- Bitmask m = pSrc->colUsed;
- int j;
- for(j=0; j<pIdx->nColumn; j++){
- int x = pIdx->aiColumn[j];
- if( x<BMS-1 ){
- m &= ~(((Bitmask)1)<<x);
- }
- }
- if( m==0 ){
- pc.plan.wsFlags |= WHERE_IDX_ONLY;
- }else{
- bLookup = 1;
- }
- }
-
- /*
- ** Estimate the number of rows of output. For an "x IN (SELECT...)"
- ** constraint, do not let the estimate exceed half the rows in the table.
- */
- pc.plan.nRow = (double)(aiRowEst[pc.plan.nEq] * nInMul);
- if( bInEst && pc.plan.nRow*2>aiRowEst[0] ){
- pc.plan.nRow = aiRowEst[0]/2;
- nInMul = (int)(pc.plan.nRow / aiRowEst[pc.plan.nEq]);
- }
-
-#ifdef SQLITE_ENABLE_STAT3
- /* If the constraint is of the form x=VALUE or x IN (E1,E2,...)
- ** and we do not think that values of x are unique and if histogram
- ** data is available for column x, then it might be possible
- ** to get a better estimate on the number of rows based on
- ** VALUE and how common that value is according to the histogram.
- */
- if( pc.plan.nRow>(double)1 && pc.plan.nEq==1
- && pFirstTerm!=0 && aiRowEst[1]>1 ){
- assert( (pFirstTerm->eOperator & (WO_EQ|WO_ISNULL|WO_IN))!=0 );
- if( pFirstTerm->eOperator & (WO_EQ|WO_ISNULL) ){
- testcase( pFirstTerm->eOperator & WO_EQ );
- testcase( pFirstTerm->eOperator & WO_EQUIV );
- testcase( pFirstTerm->eOperator & WO_ISNULL );
- whereEqualScanEst(pParse, pProbe, pFirstTerm->pExpr->pRight,
- &pc.plan.nRow);
- }else if( bInEst==0 ){
- assert( pFirstTerm->eOperator & WO_IN );
- whereInScanEst(pParse, pProbe, pFirstTerm->pExpr->x.pList,
- &pc.plan.nRow);
- }
- }
-#endif /* SQLITE_ENABLE_STAT3 */
-
- /* Adjust the number of output rows and downward to reflect rows
- ** that are excluded by range constraints.
- */
- pc.plan.nRow = pc.plan.nRow/rangeDiv;
- if( pc.plan.nRow<1 ) pc.plan.nRow = 1;
-
- /* Experiments run on real SQLite databases show that the time needed
- ** to do a binary search to locate a row in a table or index is roughly
- ** log10(N) times the time to move from one row to the next row within
- ** a table or index. The actual times can vary, with the size of
- ** records being an important factor. Both moves and searches are
- ** slower with larger records, presumably because fewer records fit
- ** on one page and hence more pages have to be fetched.
- **
- ** The ANALYZE command and the sqlite_stat1 and sqlite_stat3 tables do
- ** not give us data on the relative sizes of table and index records.
- ** So this computation assumes table records are about twice as big
- ** as index records
- */
- if( (pc.plan.wsFlags&~(WHERE_REVERSE|WHERE_ORDERED|WHERE_OB_UNIQUE))
- ==WHERE_IDX_ONLY
- && (pWC->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
- && sqlite3GlobalConfig.bUseCis
- && OptimizationEnabled(pParse->db, SQLITE_CoverIdxScan)
- ){
- /* This index is not useful for indexing, but it is a covering index.
- ** A full-scan of the index might be a little faster than a full-scan
- ** of the table, so give this case a cost slightly less than a table
- ** scan. */
- pc.rCost = aiRowEst[0]*3 + pProbe->nColumn;
- pc.plan.wsFlags |= WHERE_COVER_SCAN|WHERE_COLUMN_RANGE;
- }else if( (pc.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){
- /* The cost of a full table scan is a number of move operations equal
- ** to the number of rows in the table.
- **
- ** We add an additional 4x penalty to full table scans. This causes
- ** the cost function to err on the side of choosing an index over
- ** choosing a full scan. This 4x full-scan penalty is an arguable
- ** decision and one which we expect to revisit in the future. But
- ** it seems to be working well enough at the moment.
- */
- pc.rCost = aiRowEst[0]*4;
- pc.plan.wsFlags &= ~WHERE_IDX_ONLY;
- if( pIdx ){
- pc.plan.wsFlags &= ~WHERE_ORDERED;
- pc.plan.nOBSat = nPriorSat;
- }
- }else{
- log10N = estLog(aiRowEst[0]);
- pc.rCost = pc.plan.nRow;
- if( pIdx ){
- if( bLookup ){
- /* For an index lookup followed by a table lookup:
- ** nInMul index searches to find the start of each index range
- ** + nRow steps through the index
- ** + nRow table searches to lookup the table entry using the rowid
- */
- pc.rCost += (nInMul + pc.plan.nRow)*log10N;
- }else{
- /* For a covering index:
- ** nInMul index searches to find the initial entry
- ** + nRow steps through the index
- */
- pc.rCost += nInMul*log10N;
- }
- }else{
- /* For a rowid primary key lookup:
- ** nInMult table searches to find the initial entry for each range
- ** + nRow steps through the table
- */
- pc.rCost += nInMul*log10N;
- }
- }
-
- /* Add in the estimated cost of sorting the result. Actual experimental
- ** measurements of sorting performance in SQLite show that sorting time
- ** adds C*N*log10(N) to the cost, where N is the number of rows to be
- ** sorted and C is a factor between 1.95 and 4.3. We will split the
- ** difference and select C of 3.0.
- */
- if( bSort ){
- double m = estLog(pc.plan.nRow*(nOrderBy - pc.plan.nOBSat)/nOrderBy);
- m *= (double)(pc.plan.nOBSat ? 2 : 3);
- pc.rCost += pc.plan.nRow*m;
- }
- if( bDist ){
- pc.rCost += pc.plan.nRow*estLog(pc.plan.nRow)*3;
- }
-
- /**** Cost of using this index has now been computed ****/
-
- /* If there are additional constraints on this table that cannot
- ** be used with the current index, but which might lower the number
- ** of output rows, adjust the nRow value accordingly. This only
- ** matters if the current index is the least costly, so do not bother
- ** with this step if we already know this index will not be chosen.
- ** Also, never reduce the output row count below 2 using this step.
- **
- ** It is critical that the notValid mask be used here instead of
- ** the notReady mask. When computing an "optimal" index, the notReady
- ** mask will only have one bit set - the bit for the current table.
- ** The notValid mask, on the other hand, always has all bits set for
- ** tables that are not in outer loops. If notReady is used here instead
- ** of notValid, then a optimal index that depends on inner joins loops
- ** might be selected even when there exists an optimal index that has
- ** no such dependency.
- */
- if( pc.plan.nRow>2 && pc.rCost<=p->cost.rCost ){
- int k; /* Loop counter */
- int nSkipEq = pc.plan.nEq; /* Number of == constraints to skip */
- int nSkipRange = nBound; /* Number of < constraints to skip */
- Bitmask thisTab; /* Bitmap for pSrc */
-
- thisTab = getMask(pWC->pMaskSet, iCur);
- for(pTerm=pWC->a, k=pWC->nTerm; pc.plan.nRow>2 && k; k--, pTerm++){
- if( pTerm->wtFlags & TERM_VIRTUAL ) continue;
- if( (pTerm->prereqAll & p->notValid)!=thisTab ) continue;
- if( pTerm->eOperator & (WO_EQ|WO_IN|WO_ISNULL) ){
- if( nSkipEq ){
- /* Ignore the first pc.plan.nEq equality matches since the index
- ** has already accounted for these */
- nSkipEq--;
- }else{
- /* Assume each additional equality match reduces the result
- ** set size by a factor of 10 */
- pc.plan.nRow /= 10;
- }
- }else if( pTerm->eOperator & (WO_LT|WO_LE|WO_GT|WO_GE) ){
- if( nSkipRange ){
- /* Ignore the first nSkipRange range constraints since the index
- ** has already accounted for these */
- nSkipRange--;
- }else{
- /* Assume each additional range constraint reduces the result
- ** set size by a factor of 3. Indexed range constraints reduce
- ** the search space by a larger factor: 4. We make indexed range
- ** more selective intentionally because of the subjective
- ** observation that indexed range constraints really are more
- ** selective in practice, on average. */
- pc.plan.nRow /= 3;
- }
- }else if( (pTerm->eOperator & WO_NOOP)==0 ){
- /* Any other expression lowers the output row count by half */
- pc.plan.nRow /= 2;
- }
- }
- if( pc.plan.nRow<2 ) pc.plan.nRow = 2;
- }
-
-
- WHERETRACE((
- " nEq=%d nInMul=%d rangeDiv=%d bSort=%d bLookup=%d wsFlags=0x%08x\n"
- " notReady=0x%llx log10N=%.1f nRow=%.1f cost=%.1f\n"
- " used=0x%llx nOBSat=%d\n",
- pc.plan.nEq, nInMul, (int)rangeDiv, bSort, bLookup, pc.plan.wsFlags,
- p->notReady, log10N, pc.plan.nRow, pc.rCost, pc.used,
- pc.plan.nOBSat
- ));
-
- /* If this index is the best we have seen so far, then record this
- ** index and its cost in the p->cost structure.
- */
- if( (!pIdx || pc.plan.wsFlags) && compareCost(&pc, &p->cost) ){
- p->cost = pc;
- p->cost.plan.wsFlags &= wsFlagMask;
- p->cost.plan.u.pIdx = pIdx;
- }
-
- /* If there was an INDEXED BY clause, then only that one index is
- ** considered. */
- if( pSrc->pIndex ) break;
-
- /* Reset masks for the next index in the loop */
- wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE);
- eqTermMask = idxEqTermMask;
- }
-
- /* If there is no ORDER BY clause and the SQLITE_ReverseOrder flag
- ** is set, then reverse the order that the index will be scanned
- ** in. This is used for application testing, to help find cases
- ** where application behavior depends on the (undefined) order that
- ** SQLite outputs rows in in the absence of an ORDER BY clause. */
- if( !p->pOrderBy && pParse->db->flags & SQLITE_ReverseOrder ){
- p->cost.plan.wsFlags |= WHERE_REVERSE;
- }
-
- assert( p->pOrderBy || (p->cost.plan.wsFlags&WHERE_ORDERED)==0 );
- assert( p->cost.plan.u.pIdx==0 || (p->cost.plan.wsFlags&WHERE_ROWID_EQ)==0 );
- assert( pSrc->pIndex==0
- || p->cost.plan.u.pIdx==0
- || p->cost.plan.u.pIdx==pSrc->pIndex
- );
-
- WHERETRACE((" best index is %s cost=%.1f\n",
- p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk",
- p->cost.rCost));
-
- bestOrClauseIndex(p);
- bestAutomaticIndex(p);
- p->cost.plan.wsFlags |= eqTermMask;
-}
-
-/*
-** Find the query plan for accessing table pSrc->pTab. Write the
-** best query plan and its cost into the WhereCost object supplied
-** as the last parameter. This function may calculate the cost of
-** both real and virtual table scans.
-**
-** This function does not take ORDER BY or DISTINCT into account. Nor
-** does it remember the virtual table query plan. All it does is compute
-** the cost while determining if an OR optimization is applicable. The
-** details will be reconsidered later if the optimization is found to be
-** applicable.
-*/
-static void bestIndex(WhereBestIdx *p){
-#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( IsVirtual(p->pSrc->pTab) ){
- sqlite3_index_info *pIdxInfo = 0;
- p->ppIdxInfo = &pIdxInfo;
- bestVirtualIndex(p);
- assert( pIdxInfo!=0 || p->pParse->db->mallocFailed );
- if( pIdxInfo && pIdxInfo->needToFreeIdxStr ){
- sqlite3_free(pIdxInfo->idxStr);
- }
- sqlite3DbFree(p->pParse->db, pIdxInfo);
- }else
-#endif
- {
- bestBtreeIndex(p);
- }
-}
-
-/*
** Disable a term in the WHERE clause. Except, do not disable the term
** if it controls a LEFT OUTER JOIN and it did not originate in the ON
** or USING clause of that join.
@@ -3813,6 +2821,7 @@ static int codeEqualityTerm(
WhereTerm *pTerm, /* The term of the WHERE clause to be coded */
WhereLevel *pLevel, /* The level of the FROM clause we are working on */
int iEq, /* Index of the equality term within this level */
+ int bRev, /* True for reverse-order IN operations */
int iTarget /* Attempt to leave results in this register */
){
Expr *pX = pTerm->pExpr;
@@ -3830,14 +2839,13 @@ static int codeEqualityTerm(
int eType;
int iTab;
struct InLoop *pIn;
- u8 bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
+ WhereLoop *pLoop = pLevel->pWLoop;
- if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0
- && pLevel->plan.u.pIdx->aSortOrder[iEq]
+ if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
+ && pLoop->u.btree.pIndex!=0
+ && pLoop->u.btree.pIndex->aSortOrder[iEq]
){
testcase( iEq==0 );
- testcase( iEq==pLevel->plan.u.pIdx->nColumn-1 );
- testcase( iEq>0 && iEq+1<pLevel->plan.u.pIdx->nColumn );
testcase( bRev );
bRev = !bRev;
}
@@ -3850,7 +2858,8 @@ static int codeEqualityTerm(
}
iTab = pX->iTable;
sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
- assert( pLevel->plan.wsFlags & WHERE_IN_ABLE );
+ assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
+ pLoop->wsFlags |= WHERE_IN_ABLE;
if( pLevel->u.in.nIn==0 ){
pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
}
@@ -3920,29 +2929,31 @@ static int codeEqualityTerm(
static int codeAllEqualityTerms(
Parse *pParse, /* Parsing context */
WhereLevel *pLevel, /* Which nested loop of the FROM we are coding */
- WhereClause *pWC, /* The WHERE clause */
- Bitmask notReady, /* Which parts of FROM have not yet been coded */
+ int bRev, /* Reverse the order of IN operators */
int nExtraReg, /* Number of extra registers to allocate */
char **pzAff /* OUT: Set to point to affinity string */
){
- int nEq = pLevel->plan.nEq; /* The number of == or IN constraints to code */
+ int nEq; /* The number of == or IN constraints to code */
Vdbe *v = pParse->pVdbe; /* The vm under construction */
Index *pIdx; /* The index being used for this loop */
- int iCur = pLevel->iTabCur; /* The cursor of the table */
WhereTerm *pTerm; /* A single constraint term */
+ WhereLoop *pLoop; /* The WhereLoop object */
int j; /* Loop counter */
int regBase; /* Base register */
int nReg; /* Number of registers to allocate */
char *zAff; /* Affinity string to return */
/* This module is only called on query plans that use an index. */
- assert( pLevel->plan.wsFlags & WHERE_INDEXED );
- pIdx = pLevel->plan.u.pIdx;
+ pLoop = pLevel->pWLoop;
+ assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+ nEq = pLoop->u.btree.nEq;
+ pIdx = pLoop->u.btree.pIndex;
+ assert( pIdx!=0 );
/* Figure out how many memory cells we will need then allocate them.
*/
regBase = pParse->nMem + 1;
- nReg = pLevel->plan.nEq + nExtraReg;
+ nReg = pLoop->u.btree.nEq + nExtraReg;
pParse->nMem += nReg;
zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
@@ -3955,14 +2966,13 @@ static int codeAllEqualityTerms(
assert( pIdx->nColumn>=nEq );
for(j=0; j<nEq; j++){
int r1;
- int k = pIdx->aiColumn[j];
- pTerm = findTerm(pWC, iCur, k, notReady, pLevel->plan.wsFlags, pIdx);
- if( pTerm==0 ) break;
+ pTerm = pLoop->aLTerm[j];
+ assert( pTerm!=0 );
/* The following true for indices with redundant columns.
** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
- r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, regBase+j);
+ r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
if( r1!=regBase+j ){
if( nReg==1 ){
sqlite3ReleaseTempReg(pParse, regBase);
@@ -4030,16 +3040,15 @@ static void explainAppendTerm(
** It is the responsibility of the caller to free the buffer when it is
** no longer required.
*/
-static char *explainIndexRange(sqlite3 *db, WhereLevel *pLevel, Table *pTab){
- WherePlan *pPlan = &pLevel->plan;
- Index *pIndex = pPlan->u.pIdx;
- int nEq = pPlan->nEq;
+static char *explainIndexRange(sqlite3 *db, WhereLoop *pLoop, Table *pTab){
+ Index *pIndex = pLoop->u.btree.pIndex;
+ int nEq = pLoop->u.btree.nEq;
int i, j;
Column *aCol = pTab->aCol;
int *aiColumn = pIndex->aiColumn;
StrAccum txt;
- if( nEq==0 && (pPlan->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){
+ if( nEq==0 && (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){
return 0;
}
sqlite3StrAccumInit(&txt, 0, 0, SQLITE_MAX_LENGTH);
@@ -4050,11 +3059,11 @@ static char *explainIndexRange(sqlite3 *db, WhereLevel *pLevel, Table *pTab){
}
j = i;
- if( pPlan->wsFlags&WHERE_BTM_LIMIT ){
+ if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName;
explainAppendTerm(&txt, i++, z, ">");
}
- if( pPlan->wsFlags&WHERE_TOP_LIMIT ){
+ if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName;
explainAppendTerm(&txt, i, z, "<");
}
@@ -4077,20 +3086,22 @@ static void explainOneScan(
u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
){
if( pParse->explain==2 ){
- u32 flags = pLevel->plan.wsFlags;
struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
Vdbe *v = pParse->pVdbe; /* VM being constructed */
sqlite3 *db = pParse->db; /* Database handle */
char *zMsg; /* Text to add to EQP output */
- sqlite3_int64 nRow; /* Expected number of rows visited by scan */
int iId = pParse->iSelectId; /* Select id (left-most output column) */
int isSearch; /* True for a SEARCH. False for SCAN. */
+ WhereLoop *pLoop; /* The controlling WhereLoop object */
+ u32 flags; /* Flags that describe this loop */
+ pLoop = pLevel->pWLoop;
+ flags = pLoop->wsFlags;
if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return;
- isSearch = (pLevel->plan.nEq>0)
- || (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
- || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+ isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
+ || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
+ || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
zMsg = sqlite3MPrintf(db, "%s", isSearch?"SEARCH":"SCAN");
if( pItem->pSelect ){
@@ -4102,43 +3113,38 @@ static void explainOneScan(
if( pItem->zAlias ){
zMsg = sqlite3MAppendf(db, zMsg, "%s AS %s", zMsg, pItem->zAlias);
}
- if( (flags & WHERE_INDEXED)!=0 ){
- char *zWhere = explainIndexRange(db, pLevel, pItem->pTab);
+ if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0
+ && ALWAYS(pLoop->u.btree.pIndex!=0)
+ ){
+ char *zWhere = explainIndexRange(db, pLoop, pItem->pTab);
zMsg = sqlite3MAppendf(db, zMsg, "%s USING %s%sINDEX%s%s%s", zMsg,
((flags & WHERE_TEMP_INDEX)?"AUTOMATIC ":""),
((flags & WHERE_IDX_ONLY)?"COVERING ":""),
((flags & WHERE_TEMP_INDEX)?"":" "),
- ((flags & WHERE_TEMP_INDEX)?"": pLevel->plan.u.pIdx->zName),
+ ((flags & WHERE_TEMP_INDEX)?"": pLoop->u.btree.pIndex->zName),
zWhere
);
sqlite3DbFree(db, zWhere);
- }else if( flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
+ }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
zMsg = sqlite3MAppendf(db, zMsg, "%s USING INTEGER PRIMARY KEY", zMsg);
- if( flags&WHERE_ROWID_EQ ){
+ if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid=?)", zMsg);
}else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>? AND rowid<?)", zMsg);
}else if( flags&WHERE_BTM_LIMIT ){
zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>?)", zMsg);
- }else if( flags&WHERE_TOP_LIMIT ){
+ }else if( ALWAYS(flags&WHERE_TOP_LIMIT) ){
zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid<?)", zMsg);
}
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
- sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
zMsg = sqlite3MAppendf(db, zMsg, "%s VIRTUAL TABLE INDEX %d:%s", zMsg,
- pVtabIdx->idxNum, pVtabIdx->idxStr);
+ pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
}
#endif
- if( wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX) ){
- testcase( wctrlFlags & WHERE_ORDERBY_MIN );
- nRow = 1;
- }else{
- nRow = (sqlite3_int64)pLevel->plan.nRow;
- }
- zMsg = sqlite3MAppendf(db, zMsg, "%s (~%lld rows)", zMsg, nRow);
+ zMsg = sqlite3MAppendf(db, zMsg, "%s", zMsg);
sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg, P4_DYNAMIC);
}
}
@@ -4154,7 +3160,6 @@ static void explainOneScan(
static Bitmask codeOneLoopStart(
WhereInfo *pWInfo, /* Complete information about the WHERE clause */
int iLevel, /* Which level of pWInfo->a[] should be coded */
- u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */
Bitmask notReady /* Which tables are currently available */
){
int j, k; /* Loop counters */
@@ -4163,6 +3168,7 @@ static Bitmask codeOneLoopStart(
int omitTable; /* True if we use the index only */
int bRev; /* True if we need to scan in reverse order */
WhereLevel *pLevel; /* The where level to be coded */
+ WhereLoop *pLoop; /* The WhereLoop object being coded */
WhereClause *pWC; /* Decomposition of the entire WHERE clause */
WhereTerm *pTerm; /* A WHERE clause term */
Parse *pParse; /* Parsing context */
@@ -4176,13 +3182,14 @@ static Bitmask codeOneLoopStart(
pParse = pWInfo->pParse;
v = pParse->pVdbe;
- pWC = pWInfo->pWC;
+ pWC = &pWInfo->sWC;
pLevel = &pWInfo->a[iLevel];
+ pLoop = pLevel->pWLoop;
pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
iCur = pTabItem->iCursor;
- bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
- omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0
- && (wctrlFlags & WHERE_FORCE_TABLE)==0;
+ bRev = (pWInfo->revMask>>iLevel)&1;
+ omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0
+ && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
VdbeNoopComment((v, "Begin Join Loop %d", iLevel));
/* Create labels for the "break" and "continue" instructions
@@ -4219,47 +3226,37 @@ static Bitmask codeOneLoopStart(
}else
#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
- /* Case 0: The table is a virtual-table. Use the VFilter and VNext
+ if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+ /* Case 1: The table is a virtual-table. Use the VFilter and VNext
** to access the data.
*/
int iReg; /* P3 Value for OP_VFilter */
int addrNotFound;
- sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
- int nConstraint = pVtabIdx->nConstraint;
- struct sqlite3_index_constraint_usage *aUsage =
- pVtabIdx->aConstraintUsage;
- const struct sqlite3_index_constraint *aConstraint =
- pVtabIdx->aConstraint;
+ int nConstraint = pLoop->nLTerm;
sqlite3ExprCachePush(pParse);
iReg = sqlite3GetTempRange(pParse, nConstraint+2);
addrNotFound = pLevel->addrBrk;
- for(j=1; j<=nConstraint; j++){
- for(k=0; k<nConstraint; k++){
- if( aUsage[k].argvIndex==j ){
- int iTarget = iReg+j+1;
- pTerm = &pWC->a[aConstraint[k].iTermOffset];
- if( pTerm->eOperator & WO_IN ){
- codeEqualityTerm(pParse, pTerm, pLevel, k, iTarget);
- addrNotFound = pLevel->addrNxt;
- }else{
- sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
- }
- break;
- }
+ for(j=0; j<nConstraint; j++){
+ int iTarget = iReg+j+2;
+ pTerm = pLoop->aLTerm[j];
+ if( pTerm==0 ) continue;
+ if( pTerm->eOperator & WO_IN ){
+ codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
+ addrNotFound = pLevel->addrNxt;
+ }else{
+ sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
}
- if( k==nConstraint ) break;
}
- sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg);
- sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
- sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg, pVtabIdx->idxStr,
- pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
- pVtabIdx->needToFreeIdxStr = 0;
- for(j=0; j<nConstraint; j++){
- if( aUsage[j].omit ){
- int iTerm = aConstraint[j].iTermOffset;
- disableTerm(pLevel, &pWC->a[iTerm]);
+ sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
+ sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
+ sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
+ pLoop->u.vtab.idxStr,
+ pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
+ pLoop->u.vtab.needFree = 0;
+ for(j=0; j<nConstraint && j<16; j++){
+ if( (pLoop->u.vtab.omitMask>>j)&1 ){
+ disableTerm(pLevel, pLoop->aLTerm[j]);
}
}
pLevel->op = OP_VNext;
@@ -4270,19 +3267,22 @@ static Bitmask codeOneLoopStart(
}else
#endif /* SQLITE_OMIT_VIRTUALTABLE */
- if( pLevel->plan.wsFlags & WHERE_ROWID_EQ ){
- /* Case 1: We can directly reference a single row using an
+ if( (pLoop->wsFlags & WHERE_IPK)!=0
+ && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
+ ){
+ /* Case 2: We can directly reference a single row using an
** equality comparison against the ROWID field. Or
** we reference multiple rows using a "rowid IN (...)"
** construct.
*/
+ assert( pLoop->u.btree.nEq==1 );
iReleaseReg = sqlite3GetTempReg(pParse);
- pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
+ pTerm = pLoop->aLTerm[0];
assert( pTerm!=0 );
assert( pTerm->pExpr!=0 );
assert( omitTable==0 );
testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
- iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, iReleaseReg);
+ iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
addrNxt = pLevel->addrNxt;
sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt);
sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
@@ -4290,8 +3290,10 @@ static Bitmask codeOneLoopStart(
sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
VdbeComment((v, "pk"));
pLevel->op = OP_Noop;
- }else if( pLevel->plan.wsFlags & WHERE_ROWID_RANGE ){
- /* Case 2: We have an inequality comparison against the ROWID field.
+ }else if( (pLoop->wsFlags & WHERE_IPK)!=0
+ && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
+ ){
+ /* Case 3: We have an inequality comparison against the ROWID field.
*/
int testOp = OP_Noop;
int start;
@@ -4299,8 +3301,11 @@ static Bitmask codeOneLoopStart(
WhereTerm *pStart, *pEnd;
assert( omitTable==0 );
- pStart = findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0);
- pEnd = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0);
+ j = 0;
+ pStart = pEnd = 0;
+ if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
+ if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
+ assert( pStart!=0 || pEnd!=0 );
if( bRev ){
pTerm = pStart;
pStart = pEnd;
@@ -4355,11 +3360,7 @@ static Bitmask codeOneLoopStart(
pLevel->op = bRev ? OP_Prev : OP_Next;
pLevel->p1 = iCur;
pLevel->p2 = start;
- if( pStart==0 && pEnd==0 ){
- pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
- }else{
- assert( pLevel->p5==0 );
- }
+ assert( pLevel->p5==0 );
if( testOp!=OP_Noop ){
iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
@@ -4367,8 +3368,8 @@ static Bitmask codeOneLoopStart(
sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
}
- }else if( pLevel->plan.wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
- /* Case 3: A scan using an index.
+ }else if( pLoop->wsFlags & WHERE_INDEXED ){
+ /* Case 4: A scan using an index.
**
** The WHERE clause may contain zero or more equality
** terms ("==" or "IN" operators) that refer to the N
@@ -4414,8 +3415,8 @@ static Bitmask codeOneLoopStart(
OP_IdxGE, /* 1: (end_constraints && !bRev) */
OP_IdxLT /* 2: (end_constraints && bRev) */
};
- int nEq = pLevel->plan.nEq; /* Number of == or IN terms */
- int isMinQuery = 0; /* If this is an optimized SELECT min(x).. */
+ int nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */
+ int isMinQuery = 0; /* If this is an optimized SELECT min(x).. */
int regBase; /* Base register holding constraint values */
int r1; /* Temp register */
WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
@@ -4431,9 +3432,8 @@ static Bitmask codeOneLoopStart(
char *zStartAff; /* Affinity for start of range constraint */
char *zEndAff; /* Affinity for end of range constraint */
- pIdx = pLevel->plan.u.pIdx;
+ pIdx = pLoop->u.btree.pIndex;
iIdxCur = pLevel->iIdxCur;
- k = (nEq==pIdx->nColumn ? -1 : pIdx->aiColumn[nEq]);
/* If this loop satisfies a sort order (pOrderBy) request that
** was passed to this function to implement a "SELECT min(x) ..."
@@ -4443,8 +3443,8 @@ static Bitmask codeOneLoopStart(
** the first one after the nEq equality constraints in the index,
** this requires some special handling.
*/
- if( (wctrlFlags&WHERE_ORDERBY_MIN)!=0
- && (pLevel->plan.wsFlags&WHERE_ORDERED)
+ if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
+ && (pWInfo->bOBSat!=0)
&& (pIdx->nColumn>nEq)
){
/* assert( pOrderBy->nExpr==1 ); */
@@ -4456,12 +3456,13 @@ static Bitmask codeOneLoopStart(
/* Find any inequality constraint terms for the start and end
** of the range.
*/
- if( pLevel->plan.wsFlags & WHERE_TOP_LIMIT ){
- pRangeEnd = findTerm(pWC, iCur, k, notReady, (WO_LT|WO_LE), pIdx);
+ j = nEq;
+ if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
+ pRangeStart = pLoop->aLTerm[j++];
nExtraReg = 1;
}
- if( pLevel->plan.wsFlags & WHERE_BTM_LIMIT ){
- pRangeStart = findTerm(pWC, iCur, k, notReady, (WO_GT|WO_GE), pIdx);
+ if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
+ pRangeEnd = pLoop->aLTerm[j++];
nExtraReg = 1;
}
@@ -4469,9 +3470,7 @@ static Bitmask codeOneLoopStart(
** and store the values of those terms in an array of registers
** starting at regBase.
*/
- regBase = codeAllEqualityTerms(
- pParse, pLevel, pWC, notReady, nExtraReg, &zStartAff
- );
+ regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
zEndAff = sqlite3DbStrDup(pParse->db, zStartAff);
addrNxt = pLevel->addrNxt;
@@ -4485,10 +3484,10 @@ static Bitmask codeOneLoopStart(
SWAP(WhereTerm *, pRangeEnd, pRangeStart);
}
- testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
- testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
- testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
- testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );
+ testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
+ testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
+ testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
+ testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
start_constraints = pRangeStart || nEq>0;
@@ -4578,9 +3577,9 @@ static Bitmask codeOneLoopStart(
** If it is, jump to the next iteration of the loop.
*/
r1 = sqlite3GetTempReg(pParse);
- testcase( pLevel->plan.wsFlags & WHERE_BTM_LIMIT );
- testcase( pLevel->plan.wsFlags & WHERE_TOP_LIMIT );
- if( (pLevel->plan.wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){
+ testcase( pLoop->wsFlags & WHERE_BTM_LIMIT );
+ testcase( pLoop->wsFlags & WHERE_TOP_LIMIT );
+ if( (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
}
@@ -4599,7 +3598,7 @@ static Bitmask codeOneLoopStart(
/* Record the instruction used to terminate the loop. Disable
** WHERE clause terms made redundant by the index range scan.
*/
- if( pLevel->plan.wsFlags & WHERE_UNIQUE ){
+ if( pLoop->wsFlags & WHERE_ONEROW ){
pLevel->op = OP_Noop;
}else if( bRev ){
pLevel->op = OP_Prev;
@@ -4607,7 +3606,7 @@ static Bitmask codeOneLoopStart(
pLevel->op = OP_Next;
}
pLevel->p1 = iIdxCur;
- if( pLevel->plan.wsFlags & WHERE_COVER_SCAN ){
+ if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
}else{
assert( pLevel->p5==0 );
@@ -4615,8 +3614,8 @@ static Bitmask codeOneLoopStart(
}else
#ifndef SQLITE_OMIT_OR_OPTIMIZATION
- if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){
- /* Case 4: Two or more separately indexed terms connected by OR
+ if( pLoop->wsFlags & WHERE_MULTI_OR ){
+ /* Case 5: Two or more separately indexed terms connected by OR
**
** Example:
**
@@ -4669,7 +3668,7 @@ static Bitmask codeOneLoopStart(
int ii; /* Loop counter */
Expr *pAndExpr = 0; /* An ".. AND (...)" expression */
- pTerm = pLevel->plan.u.pTerm;
+ pTerm = pLoop->aLTerm[0];
assert( pTerm!=0 );
assert( pTerm->eOperator & WO_OR );
assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
@@ -4688,7 +3687,7 @@ static Bitmask codeOneLoopStart(
pOrTab = sqlite3StackAllocRaw(pParse->db,
sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
if( pOrTab==0 ) return notReady;
- pOrTab->nAlloc = (i16)(nNotReady + 1);
+ pOrTab->nAlloc = (u8)(nNotReady + 1);
pOrTab->nSrc = pOrTab->nAlloc;
memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
origSrc = pWInfo->pTabList->a;
@@ -4710,7 +3709,7 @@ static Bitmask codeOneLoopStart(
** fall through to the next instruction, just as an OP_Next does if
** called on an uninitialized cursor.
*/
- if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+ if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
regRowset = ++pParse->nMem;
regRowid = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
@@ -4761,11 +3760,11 @@ static Bitmask codeOneLoopStart(
WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY, iCovCur);
assert( pSubWInfo || pParse->nErr || pParse->db->mallocFailed );
if( pSubWInfo ){
- WhereLevel *pLvl;
+ WhereLoop *pSubLoop;
explainOneScan(
pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
);
- if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+ if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
int r;
r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur,
@@ -4794,13 +3793,13 @@ static Bitmask codeOneLoopStart(
** pCov to NULL to indicate that no candidate covering index will
** be available.
*/
- pLvl = &pSubWInfo->a[0];
- if( (pLvl->plan.wsFlags & WHERE_INDEXED)!=0
- && (pLvl->plan.wsFlags & WHERE_TEMP_INDEX)==0
- && (ii==0 || pLvl->plan.u.pIdx==pCov)
+ pSubLoop = pSubWInfo->a[0].pWLoop;
+ assert( (pSubLoop->wsFlags & WHERE_TEMP_INDEX)==0 );
+ if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
+ && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
){
- assert( pLvl->iIdxCur==iCovCur );
- pCov = pLvl->plan.u.pIdx;
+ assert( pSubWInfo->a[0].iIdxCur==iCovCur );
+ pCov = pSubLoop->u.btree.pIndex;
}else{
pCov = 0;
}
@@ -4826,19 +3825,18 @@ static Bitmask codeOneLoopStart(
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
{
- /* Case 5: There is no usable index. We must do a complete
+ /* Case 6: There is no usable index. We must do a complete
** scan of the entire table.
*/
static const u8 aStep[] = { OP_Next, OP_Prev };
static const u8 aStart[] = { OP_Rewind, OP_Last };
assert( bRev==0 || bRev==1 );
- assert( omitTable==0 );
pLevel->op = aStep[bRev];
pLevel->p1 = iCur;
pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
}
- newNotReady = notReady & ~getMask(pWC->pMaskSet, iCur);
+ newNotReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur);
/* Insert code to test every subexpression that can be completely
** computed using the current set of tables.
@@ -4888,6 +3886,8 @@ static Bitmask codeOneLoopStart(
pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
if( pAlt==0 ) continue;
if( pAlt->wtFlags & (TERM_CODED) ) continue;
+ testcase( pAlt->eOperator & WO_EQ );
+ testcase( pAlt->eOperator & WO_IN );
VdbeNoopComment((v, "begin transitive constraint"));
sEq = *pAlt->pExpr;
sEq.pLeft = pE->pLeft;
@@ -4920,47 +3920,1561 @@ static Bitmask codeOneLoopStart(
return newNotReady;
}
-#if defined(SQLITE_TEST)
+#ifdef WHERETRACE_ENABLED
+/*
+** Print a WhereLoop object for debugging purposes
+*/
+static void whereLoopPrint(WhereLoop *p, SrcList *pTabList){
+ int nb = 1+(pTabList->nSrc+7)/8;
+ struct SrcList_item *pItem = pTabList->a + p->iTab;
+ Table *pTab = pItem->pTab;
+ sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
+ p->iTab, nb, p->maskSelf, nb, p->prereq);
+ sqlite3DebugPrintf(" %12s",
+ pItem->zAlias ? pItem->zAlias : pTab->zName);
+ if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+ if( p->u.btree.pIndex ){
+ const char *zName = p->u.btree.pIndex->zName;
+ if( zName==0 ) zName = "ipk";
+ if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
+ int i = sqlite3Strlen30(zName) - 1;
+ while( zName[i]!='_' ) i--;
+ zName += i;
+ }
+ sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
+ }else{
+ sqlite3DebugPrintf("%20s","");
+ }
+ }else{
+ char *z;
+ if( p->u.vtab.idxStr ){
+ z = sqlite3_mprintf("(%d,\"%s\",%x)",
+ p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
+ }else{
+ z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
+ }
+ sqlite3DebugPrintf(" %-19s", z);
+ sqlite3_free(z);
+ }
+ sqlite3DebugPrintf(" f %04x N %d", p->wsFlags, p->nLTerm);
+ sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
+}
+#endif
+
+/*
+** Convert bulk memory into a valid WhereLoop that can be passed
+** to whereLoopClear harmlessly.
+*/
+static void whereLoopInit(WhereLoop *p){
+ p->aLTerm = p->aLTermSpace;
+ p->nLTerm = 0;
+ p->nLSlot = ArraySize(p->aLTermSpace);
+ p->wsFlags = 0;
+}
+
+/*
+** Clear the WhereLoop.u union. Leave WhereLoop.pLTerm intact.
+*/
+static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
+ if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_TEMP_INDEX) ){
+ if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
+ sqlite3_free(p->u.vtab.idxStr);
+ p->u.vtab.needFree = 0;
+ p->u.vtab.idxStr = 0;
+ }else if( (p->wsFlags & WHERE_TEMP_INDEX)!=0 && p->u.btree.pIndex!=0 ){
+ sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
+ sqlite3DbFree(db, p->u.btree.pIndex);
+ p->u.btree.pIndex = 0;
+ }
+ }
+}
+
/*
-** The following variable holds a text description of query plan generated
-** by the most recent call to sqlite3WhereBegin(). Each call to WhereBegin
-** overwrites the previous. This information is used for testing and
-** analysis only.
+** Deallocate internal memory used by a WhereLoop object
*/
-char sqlite3_query_plan[BMS*2*40]; /* Text of the join */
-static int nQPlan = 0; /* Next free slow in _query_plan[] */
+static void whereLoopClear(sqlite3 *db, WhereLoop *p){
+ if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+ whereLoopClearUnion(db, p);
+ whereLoopInit(p);
+}
-#endif /* SQLITE_TEST */
+/*
+** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
+*/
+static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
+ WhereTerm **paNew;
+ if( p->nLSlot>=n ) return SQLITE_OK;
+ n = (n+7)&~7;
+ paNew = sqlite3DbMallocRaw(db, sizeof(p->aLTerm[0])*n);
+ if( paNew==0 ) return SQLITE_NOMEM;
+ memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
+ if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+ p->aLTerm = paNew;
+ p->nLSlot = n;
+ return SQLITE_OK;
+}
+/*
+** Transfer content from the second pLoop into the first.
+*/
+static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
+ if( whereLoopResize(db, pTo, pFrom->nLTerm) ) return SQLITE_NOMEM;
+ whereLoopClearUnion(db, pTo);
+ memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
+ memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
+ if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
+ pFrom->u.vtab.needFree = 0;
+ }else if( (pFrom->wsFlags & WHERE_TEMP_INDEX)!=0 ){
+ pFrom->u.btree.pIndex = 0;
+ }
+ return SQLITE_OK;
+}
+
+/*
+** Delete a WhereLoop object
+*/
+static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
+ whereLoopClear(db, p);
+ sqlite3DbFree(db, p);
+}
/*
** Free a WhereInfo structure
*/
static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
if( ALWAYS(pWInfo) ){
- int i;
- for(i=0; i<pWInfo->nLevel; i++){
- sqlite3_index_info *pInfo = pWInfo->a[i].pIdxInfo;
- if( pInfo ){
- /* assert( pInfo->needToFreeIdxStr==0 || db->mallocFailed ); */
- if( pInfo->needToFreeIdxStr ){
- sqlite3_free(pInfo->idxStr);
+ whereClauseClear(&pWInfo->sWC);
+ while( pWInfo->pLoops ){
+ WhereLoop *p = pWInfo->pLoops;
+ pWInfo->pLoops = p->pNextLoop;
+ whereLoopDelete(db, p);
+ }
+ sqlite3DbFree(db, pWInfo);
+ }
+}
+
+/*
+** Insert or replace a WhereLoop entry using the template supplied.
+**
+** An existing WhereLoop entry might be overwritten if the new template
+** is better and has fewer dependencies. Or the template will be ignored
+** and no insert will occur if an existing WhereLoop is faster and has
+** fewer dependencies than the template. Otherwise a new WhereLoop is
+** added based on the template.
+**
+** If pBuilder->pBest is not NULL then we only care about the very
+** best template and that template should be stored in pBuilder->pBest.
+** If pBuilder->pBest is NULL then a list of the best templates are stored
+** in pBuilder->pWInfo->pLoops.
+**
+** When accumulating multiple loops (when pBuilder->pBest is NULL) we
+** still might overwrite similar loops with the new template if the
+** template is better. Loops may be overwritten if the following
+** conditions are met:
+**
+** (1) They have the same iTab.
+** (2) They have the same iSortIdx.
+** (3) The template has same or fewer dependencies than the current loop
+** (4) The template has the same or lower cost than the current loop
+** (5) The template uses more terms of the same index but has no additional
+** dependencies
+*/
+static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
+ WhereLoop **ppPrev, *p, *pNext = 0;
+ WhereInfo *pWInfo = pBuilder->pWInfo;
+ sqlite3 *db = pWInfo->pParse->db;
+
+ /* If pBuilder->pBest is defined, then only keep track of the single
+ ** best WhereLoop. pBuilder->pBest->maskSelf==0 indicates that no
+ ** prior WhereLoops have been evaluated and that the current pTemplate
+ ** is therefore the first and hence the best and should be retained.
+ */
+ if( (p = pBuilder->pBest)!=0 ){
+ if( p->maskSelf!=0 ){
+ WhereCost rCost = whereCostAdd(p->rRun,p->rSetup);
+ WhereCost rTemplate = whereCostAdd(pTemplate->rRun,pTemplate->rSetup);
+ if( rCost < rTemplate ){
+ testcase( rCost==rTemplate-1 );
+ goto whereLoopInsert_noop;
+ }
+ if( rCost==rTemplate && (p->prereq & pTemplate->prereq)==p->prereq ){
+ goto whereLoopInsert_noop;
+ }
+ }
+#if WHERETRACE_ENABLED
+ if( sqlite3WhereTrace & 0x8 ){
+ sqlite3DebugPrintf(p->maskSelf==0 ? "ins-init: " : "ins-best: ");
+ whereLoopPrint(pTemplate, pWInfo->pTabList);
+ }
+#endif
+ whereLoopXfer(db, p, pTemplate);
+ return SQLITE_OK;
+ }
+
+ /* Search for an existing WhereLoop to overwrite, or which takes
+ ** priority over pTemplate.
+ */
+ for(ppPrev=&pWInfo->pLoops, p=*ppPrev; p; ppPrev=&p->pNextLoop, p=*ppPrev){
+ if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
+ /* If either the iTab or iSortIdx values for two WhereLoop are different
+ ** then those WhereLoops need to be considered separately. Neither is
+ ** a candidate to replace the other. */
+ continue;
+ }
+ /* In the current implementation, the rSetup value is either zero
+ ** or the cost of building an automatic index (NlogN) and the NlogN
+ ** is the same for compatible WhereLoops. */
+ assert( p->rSetup==0 || pTemplate->rSetup==0
+ || p->rSetup==pTemplate->rSetup );
+
+ /* whereLoopAddBtree() always generates and inserts the automatic index
+ ** case first. Hence compatible candidate WhereLoops never have a larger
+ ** rSetup. Call this SETUP-INVARIANT */
+ assert( p->rSetup>=pTemplate->rSetup );
+
+ if( (p->prereq & pTemplate->prereq)==p->prereq
+ && p->rSetup<=pTemplate->rSetup
+ && p->rRun<=pTemplate->rRun
+ ){
+ /* This branch taken when p is equal or better than pTemplate in
+ ** all of (1) dependences (2) setup-cost, and (3) run-cost. */
+ assert( p->rSetup==pTemplate->rSetup );
+ if( p->nLTerm<pTemplate->nLTerm
+ && (p->wsFlags & WHERE_INDEXED)!=0
+ && (pTemplate->wsFlags & WHERE_INDEXED)!=0
+ && p->u.btree.pIndex==pTemplate->u.btree.pIndex
+ && p->prereq==pTemplate->prereq
+ ){
+ /* Overwrite an existing WhereLoop with an similar one that uses
+ ** more terms of the index */
+ pNext = p->pNextLoop;
+ break;
+ }else{
+ /* pTemplate is not helpful.
+ ** Return without changing or adding anything */
+ goto whereLoopInsert_noop;
+ }
+ }
+ if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
+ && p->rRun>=pTemplate->rRun
+ && ALWAYS(p->rSetup>=pTemplate->rSetup) /* See SETUP-INVARIANT above */
+ ){
+ /* Overwrite an existing WhereLoop with a better one: one that is
+ ** better at one of (1) dependences, (2) setup-cost, or (3) run-cost
+ ** and is no worse in any of those categories. */
+ pNext = p->pNextLoop;
+ break;
+ }
+ }
+
+ /* If we reach this point it means that either p[] should be overwritten
+ ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
+ ** WhereLoop and insert it.
+ */
+#if WHERETRACE_ENABLED
+ if( sqlite3WhereTrace & 0x8 ){
+ if( p!=0 ){
+ sqlite3DebugPrintf("ins-del: ");
+ whereLoopPrint(p, pWInfo->pTabList);
+ }
+ sqlite3DebugPrintf("ins-new: ");
+ whereLoopPrint(pTemplate, pWInfo->pTabList);
+ }
+#endif
+ if( p==0 ){
+ p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
+ if( p==0 ) return SQLITE_NOMEM;
+ whereLoopInit(p);
+ }
+ whereLoopXfer(db, p, pTemplate);
+ p->pNextLoop = pNext;
+ *ppPrev = p;
+ if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+ Index *pIndex = p->u.btree.pIndex;
+ if( pIndex && pIndex->tnum==0 ){
+ p->u.btree.pIndex = 0;
+ }
+ }
+ return SQLITE_OK;
+
+ /* Jump here if the insert is a no-op */
+whereLoopInsert_noop:
+#if WHERETRACE_ENABLED
+ if( sqlite3WhereTrace & 0x8 ){
+ sqlite3DebugPrintf(pBuilder->pBest ? "ins-skip: " : "ins-noop: ");
+ whereLoopPrint(pTemplate, pWInfo->pTabList);
+ }
+#endif
+ return SQLITE_OK;
+}
+
+/*
+** We have so far matched pBuilder->pNew->u.btree.nEq terms of the index pIndex.
+** Try to match one more.
+**
+** If pProbe->tnum==0, that means pIndex is a fake index used for the
+** INTEGER PRIMARY KEY.
+*/
+static int whereLoopAddBtreeIndex(
+ WhereLoopBuilder *pBuilder, /* The WhereLoop factory */
+ struct SrcList_item *pSrc, /* FROM clause term being analyzed */
+ Index *pProbe, /* An index on pSrc */
+ WhereCost nInMul /* log(Number of iterations due to IN) */
+){
+ WhereInfo *pWInfo = pBuilder->pWInfo; /* WHERE analyse context */
+ Parse *pParse = pWInfo->pParse; /* Parsing context */
+ sqlite3 *db = pParse->db; /* Database connection malloc context */
+ WhereLoop *pNew; /* Template WhereLoop under construction */
+ WhereTerm *pTerm; /* A WhereTerm under consideration */
+ int opMask; /* Valid operators for constraints */
+ WhereScan scan; /* Iterator for WHERE terms */
+ Bitmask saved_prereq; /* Original value of pNew->prereq */
+ u16 saved_nLTerm; /* Original value of pNew->nLTerm */
+ int saved_nEq; /* Original value of pNew->u.btree.nEq */
+ u32 saved_wsFlags; /* Original value of pNew->wsFlags */
+ WhereCost saved_nOut; /* Original value of pNew->nOut */
+ int iCol; /* Index of the column in the table */
+ int rc = SQLITE_OK; /* Return code */
+ WhereCost nRowEst; /* Estimated index selectivity */
+ WhereCost rLogSize; /* Logarithm of table size */
+ WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
+
+ pNew = pBuilder->pNew;
+ if( db->mallocFailed ) return SQLITE_NOMEM;
+
+ assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
+ assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
+ if( pNew->wsFlags & WHERE_BTM_LIMIT ){
+ opMask = WO_LT|WO_LE;
+ }else if( pProbe->tnum<=0 || (pSrc->jointype & JT_LEFT)!=0 ){
+ opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE;
+ }else{
+ opMask = WO_EQ|WO_IN|WO_ISNULL|WO_GT|WO_GE|WO_LT|WO_LE;
+ }
+ if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
+
+ assert( pNew->u.btree.nEq<=pProbe->nColumn );
+ if( pNew->u.btree.nEq < pProbe->nColumn ){
+ iCol = pProbe->aiColumn[pNew->u.btree.nEq];
+ nRowEst = whereCost(pProbe->aiRowEst[pNew->u.btree.nEq+1]);
+ if( nRowEst==0 && pProbe->onError==OE_None ) nRowEst = 1;
+ }else{
+ iCol = -1;
+ nRowEst = 0;
+ }
+ pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol,
+ opMask, pProbe);
+ saved_nEq = pNew->u.btree.nEq;
+ saved_nLTerm = pNew->nLTerm;
+ saved_wsFlags = pNew->wsFlags;
+ saved_prereq = pNew->prereq;
+ saved_nOut = pNew->nOut;
+ pNew->rSetup = 0;
+ rLogSize = estLog(whereCost(pProbe->aiRowEst[0]));
+ for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
+ int nIn = 0;
+ if( pTerm->prereqRight & pNew->maskSelf ) continue;
+ pNew->wsFlags = saved_wsFlags;
+ pNew->u.btree.nEq = saved_nEq;
+ pNew->nLTerm = saved_nLTerm;
+ if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+ pNew->aLTerm[pNew->nLTerm++] = pTerm;
+ pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
+ pNew->rRun = rLogSize; /* Baseline cost is log2(N). Adjustments below */
+ if( pTerm->eOperator & WO_IN ){
+ Expr *pExpr = pTerm->pExpr;
+ pNew->wsFlags |= WHERE_COLUMN_IN;
+ if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+ /* "x IN (SELECT ...)": TUNING: the SELECT returns 25 rows */
+ nIn = 46; assert( 46==whereCost(25) );
+ }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
+ /* "x IN (value, value, ...)" */
+ nIn = whereCost(pExpr->x.pList->nExpr);
+ }
+ pNew->rRun += nIn;
+ pNew->u.btree.nEq++;
+ pNew->nOut = nRowEst + nInMul + nIn;
+ }else if( pTerm->eOperator & (WO_EQ) ){
+ assert( (pNew->wsFlags & (WHERE_COLUMN_NULL|WHERE_COLUMN_IN))!=0
+ || nInMul==0 );
+ pNew->wsFlags |= WHERE_COLUMN_EQ;
+ if( iCol<0
+ || (pProbe->onError!=OE_None && nInMul==0
+ && pNew->u.btree.nEq==pProbe->nColumn-1)
+ ){
+ assert( (pNew->wsFlags & WHERE_COLUMN_IN)==0 || iCol<0 );
+ pNew->wsFlags |= WHERE_ONEROW;
+ }
+ pNew->u.btree.nEq++;
+ pNew->nOut = nRowEst + nInMul;
+ }else if( pTerm->eOperator & (WO_ISNULL) ){
+ pNew->wsFlags |= WHERE_COLUMN_NULL;
+ pNew->u.btree.nEq++;
+ /* TUNING: IS NULL selects 2 rows */
+ nIn = 10; assert( 10==whereCost(2) );
+ pNew->nOut = nRowEst + nInMul + nIn;
+ }else if( pTerm->eOperator & (WO_GT|WO_GE) ){
+ testcase( pTerm->eOperator & WO_GT );
+ testcase( pTerm->eOperator & WO_GE );
+ pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
+ pBtm = pTerm;
+ pTop = 0;
+ }else{
+ assert( pTerm->eOperator & (WO_LT|WO_LE) );
+ testcase( pTerm->eOperator & WO_LT );
+ testcase( pTerm->eOperator & WO_LE );
+ pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
+ pTop = pTerm;
+ pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
+ pNew->aLTerm[pNew->nLTerm-2] : 0;
+ }
+ if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+ /* Adjust nOut and rRun for STAT3 range values */
+ WhereCost rDiv;
+ whereRangeScanEst(pParse, pProbe, pNew->u.btree.nEq,
+ pBtm, pTop, &rDiv);
+ pNew->nOut = saved_nOut>rDiv+10 ? saved_nOut - rDiv : 10;
+ }
+#ifdef SQLITE_ENABLE_STAT3
+ if( pNew->u.btree.nEq==1 && pProbe->nSample ){
+ tRowcnt nOut = 0;
+ if( (pTerm->eOperator & (WO_EQ|WO_ISNULL))!=0 ){
+ testcase( pTerm->eOperator & WO_EQ );
+ testcase( pTerm->eOperator & WO_ISNULL );
+ rc = whereEqualScanEst(pParse, pProbe, pTerm->pExpr->pRight, &nOut);
+ }else if( (pTerm->eOperator & WO_IN)
+ && !ExprHasProperty(pTerm->pExpr, EP_xIsSelect) ){
+ rc = whereInScanEst(pParse, pProbe, pTerm->pExpr->x.pList, &nOut);
+ }
+ if( rc==SQLITE_OK ) pNew->nOut = whereCost(nOut);
+ }
+#endif
+ if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
+ /* Each row involves a step of the index, then a binary search of
+ ** the main table */
+ pNew->rRun = whereCostAdd(pNew->rRun, rLogSize>27 ? rLogSize-17 : 10);
+ }
+ /* Step cost for each output row */
+ pNew->rRun = whereCostAdd(pNew->rRun, pNew->nOut);
+ /* TBD: Adjust nOut for additional constraints */
+ rc = whereLoopInsert(pBuilder, pNew);
+ if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
+ && pNew->u.btree.nEq<(pProbe->nColumn + (pProbe->zName!=0))
+ ){
+ whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
+ }
+ }
+ pNew->prereq = saved_prereq;
+ pNew->u.btree.nEq = saved_nEq;
+ pNew->wsFlags = saved_wsFlags;
+ pNew->nOut = saved_nOut;
+ pNew->nLTerm = saved_nLTerm;
+ return rc;
+}
+
+/*
+** Return True if it is possible that pIndex might be useful in
+** implementing the ORDER BY clause in pBuilder.
+**
+** Return False if pBuilder does not contain an ORDER BY clause or
+** if there is no way for pIndex to be useful in implementing that
+** ORDER BY clause.
+*/
+static int indexMightHelpWithOrderBy(
+ WhereLoopBuilder *pBuilder,
+ Index *pIndex,
+ int iCursor
+){
+ ExprList *pOB;
+ int ii, jj;
+
+ if( pIndex->bUnordered ) return 0;
+ if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
+ for(ii=0; ii<pOB->nExpr; ii++){
+ Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);
+ if( pExpr->op!=TK_COLUMN ) return 0;
+ if( pExpr->iTable==iCursor ){
+ for(jj=0; jj<pIndex->nColumn; jj++){
+ if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+** Return a bitmask where 1s indicate that the corresponding column of
+** the table is used by an index. Only the first 63 columns are considered.
+*/
+static Bitmask columnsInIndex(Index *pIdx){
+ Bitmask m = 0;
+ int j;
+ for(j=pIdx->nColumn-1; j>=0; j--){
+ int x = pIdx->aiColumn[j];
+ testcase( x==BMS-1 );
+ testcase( x==BMS-2 );
+ if( x<BMS-1 ) m |= MASKBIT(x);
+ }
+ return m;
+}
+
+
+/*
+** Add all WhereLoop objects a single table of the join were the table
+** is idenfied by pBuilder->pNew->iTab. That table is guaranteed to be
+** a b-tree table, not a virtual table.
+*/
+static int whereLoopAddBtree(
+ WhereLoopBuilder *pBuilder, /* WHERE clause information */
+ Bitmask mExtra /* Extra prerequesites for using this table */
+){
+ WhereInfo *pWInfo; /* WHERE analysis context */
+ Index *pProbe; /* An index we are evaluating */
+ Index sPk; /* A fake index object for the primary key */
+ tRowcnt aiRowEstPk[2]; /* The aiRowEst[] value for the sPk index */
+ int aiColumnPk = -1; /* The aColumn[] value for the sPk index */
+ SrcList *pTabList; /* The FROM clause */
+ struct SrcList_item *pSrc; /* The FROM clause btree term to add */
+ WhereLoop *pNew; /* Template WhereLoop object */
+ int rc = SQLITE_OK; /* Return code */
+ int iSortIdx = 1; /* Index number */
+ int b; /* A boolean value */
+ WhereCost rSize; /* number of rows in the table */
+ WhereCost rLogSize; /* Logarithm of the number of rows in the table */
+
+ pNew = pBuilder->pNew;
+ pWInfo = pBuilder->pWInfo;
+ pTabList = pWInfo->pTabList;
+ pSrc = pTabList->a + pNew->iTab;
+ assert( !IsVirtual(pSrc->pTab) );
+
+ if( pSrc->pIndex ){
+ /* An INDEXED BY clause specifies a particular index to use */
+ pProbe = pSrc->pIndex;
+ }else{
+ /* There is no INDEXED BY clause. Create a fake Index object in local
+ ** variable sPk to represent the rowid primary key index. Make this
+ ** fake index the first in a chain of Index objects with all of the real
+ ** indices to follow */
+ Index *pFirst; /* First of real indices on the table */
+ memset(&sPk, 0, sizeof(Index));
+ sPk.nColumn = 1;
+ sPk.aiColumn = &aiColumnPk;
+ sPk.aiRowEst = aiRowEstPk;
+ sPk.onError = OE_Replace;
+ sPk.pTable = pSrc->pTab;
+ aiRowEstPk[0] = pSrc->pTab->nRowEst;
+ aiRowEstPk[1] = 1;
+ pFirst = pSrc->pTab->pIndex;
+ if( pSrc->notIndexed==0 ){
+ /* The real indices of the table are only considered if the
+ ** NOT INDEXED qualifier is omitted from the FROM clause */
+ sPk.pNext = pFirst;
+ }
+ pProbe = &sPk;
+ }
+ rSize = whereCost(pSrc->pTab->nRowEst);
+ rLogSize = estLog(rSize);
+
+ /* Automatic indexes */
+ if( !pBuilder->pBest
+ && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
+ && pSrc->pIndex==0
+ && !pSrc->viaCoroutine
+ && !pSrc->notIndexed
+ && !pSrc->isCorrelated
+ ){
+ /* Generate auto-index WhereLoops */
+ WhereClause *pWC = pBuilder->pWC;
+ WhereTerm *pTerm;
+ WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
+ for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
+ if( pTerm->prereqRight & pNew->maskSelf ) continue;
+ if( termCanDriveIndex(pTerm, pSrc, 0) ){
+ pNew->u.btree.nEq = 1;
+ pNew->u.btree.pIndex = 0;
+ pNew->nLTerm = 1;
+ pNew->aLTerm[0] = pTerm;
+ /* TUNING: One-time cost for computing the automatic index is
+ ** approximately 6*N*log2(N) where N is the number of rows in
+ ** the table being indexed. */
+ pNew->rSetup = rLogSize + rSize + 26; assert( 26==whereCost(6) );
+ /* TUNING: Each index lookup yields 10 rows in the table */
+ pNew->nOut = 33; assert( 33==whereCost(10) );
+ pNew->rRun = whereCostAdd(rLogSize,pNew->nOut);
+ pNew->wsFlags = WHERE_TEMP_INDEX;
+ pNew->prereq = mExtra | pTerm->prereqRight;
+ rc = whereLoopInsert(pBuilder, pNew);
+ }
+ }
+ }
+
+ /* Loop over all indices
+ */
+ for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
+ pNew->u.btree.nEq = 0;
+ pNew->nLTerm = 0;
+ pNew->iSortIdx = 0;
+ pNew->rSetup = 0;
+ pNew->prereq = mExtra;
+ pNew->nOut = rSize;
+ pNew->u.btree.pIndex = pProbe;
+ b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
+ /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
+ assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
+ if( pProbe->tnum<=0 ){
+ /* Integer primary key index */
+ pNew->wsFlags = WHERE_IPK;
+
+ /* Full table scan */
+ pNew->iSortIdx = b ? iSortIdx : 0;
+ /* TUNING: Cost of full table scan is 3*(N + log2(N)).
+ ** + The extra 3 factor is to encourage the use of indexed lookups
+ ** over full scans. A smaller constant 2 is used for covering
+ ** index scans so that a covering index scan will be favored over
+ ** a table scan. */
+ pNew->rRun = whereCostAdd(rSize,rLogSize) + 16;
+ rc = whereLoopInsert(pBuilder, pNew);
+ if( rc ) break;
+ }else{
+ Bitmask m = pSrc->colUsed & ~columnsInIndex(pProbe);
+ pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
+
+ /* Full scan via index */
+ if( b
+ || ( m==0
+ && pProbe->bUnordered==0
+ && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
+ && sqlite3GlobalConfig.bUseCis
+ && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+ )
+ ){
+ pNew->iSortIdx = b ? iSortIdx : 0;
+ if( m==0 ){
+ /* TUNING: Cost of a covering index scan is 2*(N + log2(N)).
+ ** + The extra 2 factor is to encourage the use of indexed lookups
+ ** over index scans. A table scan uses a factor of 3 so that
+ ** index scans are favored over table scans.
+ ** + If this covering index might also help satisfy the ORDER BY
+ ** clause, then the cost is fudged down slightly so that this
+ ** index is favored above other indices that have no hope of
+ ** helping with the ORDER BY. */
+ pNew->rRun = 10 + whereCostAdd(rSize,rLogSize) - b;
+ }else{
+ assert( b!=0 );
+ /* TUNING: Cost of scanning a non-covering index is (N+1)*log2(N)
+ ** which we will simplify to just N*log2(N) */
+ pNew->rRun = rSize + rLogSize;
}
- sqlite3DbFree(db, pInfo);
+ rc = whereLoopInsert(pBuilder, pNew);
+ if( rc ) break;
}
- if( pWInfo->a[i].plan.wsFlags & WHERE_TEMP_INDEX ){
- Index *pIdx = pWInfo->a[i].plan.u.pIdx;
- if( pIdx ){
- sqlite3DbFree(db, pIdx->zColAff);
- sqlite3DbFree(db, pIdx);
+ }
+ rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
+
+ /* If there was an INDEXED BY clause, then only that one index is
+ ** considered. */
+ if( pSrc->pIndex ) break;
+ }
+ return rc;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Add all WhereLoop objects for a table of the join identified by
+** pBuilder->pNew->iTab. That table is guaranteed to be a virtual table.
+*/
+static int whereLoopAddVirtual(
+ WhereLoopBuilder *pBuilder /* WHERE clause information */
+){
+ WhereInfo *pWInfo; /* WHERE analysis context */
+ Parse *pParse; /* The parsing context */
+ WhereClause *pWC; /* The WHERE clause */
+ struct SrcList_item *pSrc; /* The FROM clause term to search */
+ Table *pTab;
+ sqlite3 *db;
+ sqlite3_index_info *pIdxInfo;
+ struct sqlite3_index_constraint *pIdxCons;
+ struct sqlite3_index_constraint_usage *pUsage;
+ WhereTerm *pTerm;
+ int i, j;
+ int iTerm, mxTerm;
+ int nConstraint;
+ int seenIn = 0; /* True if an IN operator is seen */
+ int seenVar = 0; /* True if a non-constant constraint is seen */
+ int iPhase; /* 0: const w/o IN, 1: const, 2: no IN, 2: IN */
+ WhereLoop *pNew;
+ int rc = SQLITE_OK;
+
+ pWInfo = pBuilder->pWInfo;
+ pParse = pWInfo->pParse;
+ db = pParse->db;
+ pWC = pBuilder->pWC;
+ pNew = pBuilder->pNew;
+ pSrc = &pWInfo->pTabList->a[pNew->iTab];
+ pTab = pSrc->pTab;
+ assert( IsVirtual(pTab) );
+ pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pBuilder->pOrderBy);
+ if( pIdxInfo==0 ) return SQLITE_NOMEM;
+ pNew->prereq = 0;
+ pNew->rSetup = 0;
+ pNew->wsFlags = WHERE_VIRTUALTABLE;
+ pNew->nLTerm = 0;
+ pNew->u.vtab.needFree = 0;
+ pUsage = pIdxInfo->aConstraintUsage;
+ nConstraint = pIdxInfo->nConstraint;
+ if( whereLoopResize(db, pNew, nConstraint) ){
+ sqlite3DbFree(db, pIdxInfo);
+ return SQLITE_NOMEM;
+ }
+
+ for(iPhase=0; iPhase<=3; iPhase++){
+ if( !seenIn && (iPhase&1)!=0 ){
+ iPhase++;
+ if( iPhase>3 ) break;
+ }
+ if( !seenVar && iPhase>1 ) break;
+ pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+ for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
+ j = pIdxCons->iTermOffset;
+ pTerm = &pWC->a[j];
+ switch( iPhase ){
+ case 0: /* Constants without IN operator */
+ pIdxCons->usable = 0;
+ if( (pTerm->eOperator & WO_IN)!=0 ){
+ seenIn = 1;
+ }
+ if( pTerm->prereqRight!=0 ){
+ seenVar = 1;
+ }else if( (pTerm->eOperator & WO_IN)==0 ){
+ pIdxCons->usable = 1;
+ }
+ break;
+ case 1: /* Constants with IN operators */
+ assert( seenIn );
+ pIdxCons->usable = (pTerm->prereqRight==0);
+ break;
+ case 2: /* Variables without IN */
+ assert( seenVar );
+ pIdxCons->usable = (pTerm->eOperator & WO_IN)==0;
+ break;
+ default: /* Variables with IN */
+ assert( seenVar && seenIn );
+ pIdxCons->usable = 1;
+ break;
+ }
+ }
+ memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
+ if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
+ pIdxInfo->idxStr = 0;
+ pIdxInfo->idxNum = 0;
+ pIdxInfo->needToFreeIdxStr = 0;
+ pIdxInfo->orderByConsumed = 0;
+ pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
+ rc = vtabBestIndex(pParse, pTab, pIdxInfo);
+ if( rc ) goto whereLoopAddVtab_exit;
+ pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+ pNew->prereq = 0;
+ mxTerm = -1;
+ assert( pNew->nLSlot>=nConstraint );
+ for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
+ pNew->u.vtab.omitMask = 0;
+ for(i=0; i<nConstraint; i++, pIdxCons++){
+ if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
+ j = pIdxCons->iTermOffset;
+ if( iTerm>=nConstraint
+ || j<0
+ || j>=pWC->nTerm
+ || pNew->aLTerm[iTerm]!=0
+ ){
+ rc = SQLITE_ERROR;
+ sqlite3ErrorMsg(pParse, "%s.xBestIndex() malfunction", pTab->zName);
+ goto whereLoopAddVtab_exit;
+ }
+ testcase( iTerm==nConstraint-1 );
+ testcase( j==0 );
+ testcase( j==pWC->nTerm-1 );
+ pTerm = &pWC->a[j];
+ pNew->prereq |= pTerm->prereqRight;
+ assert( iTerm<pNew->nLSlot );
+ pNew->aLTerm[iTerm] = pTerm;
+ if( iTerm>mxTerm ) mxTerm = iTerm;
+ testcase( iTerm==15 );
+ testcase( iTerm==16 );
+ if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<<iTerm;
+ if( (pTerm->eOperator & WO_IN)!=0 ){
+ if( pUsage[i].omit==0 ){
+ /* Do not attempt to use an IN constraint if the virtual table
+ ** says that the equivalent EQ constraint cannot be safely omitted.
+ ** If we do attempt to use such a constraint, some rows might be
+ ** repeated in the output. */
+ break;
+ }
+ /* A virtual table that is constrained by an IN clause may not
+ ** consume the ORDER BY clause because (1) the order of IN terms
+ ** is not necessarily related to the order of output terms and
+ ** (2) Multiple outputs from a single IN value will not merge
+ ** together. */
+ pIdxInfo->orderByConsumed = 0;
}
}
}
- whereClauseClear(pWInfo->pWC);
- sqlite3DbFree(db, pWInfo);
+ if( i>=nConstraint ){
+ pNew->nLTerm = mxTerm+1;
+ assert( pNew->nLTerm<=pNew->nLSlot );
+ pNew->u.vtab.idxNum = pIdxInfo->idxNum;
+ pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
+ pIdxInfo->needToFreeIdxStr = 0;
+ pNew->u.vtab.idxStr = pIdxInfo->idxStr;
+ pNew->u.vtab.isOrdered = (u8)((pIdxInfo->nOrderBy!=0)
+ && pIdxInfo->orderByConsumed);
+ pNew->rSetup = 0;
+ pNew->rRun = whereCostFromDouble(pIdxInfo->estimatedCost);
+ /* TUNING: Every virtual table query returns 25 rows */
+ pNew->nOut = 46; assert( 46==whereCost(25) );
+ whereLoopInsert(pBuilder, pNew);
+ if( pNew->u.vtab.needFree ){
+ sqlite3_free(pNew->u.vtab.idxStr);
+ pNew->u.vtab.needFree = 0;
+ }
+ }
+ }
+
+whereLoopAddVtab_exit:
+ if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
+ sqlite3DbFree(db, pIdxInfo);
+ return rc;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Add WhereLoop entries to handle OR terms. This works for either
+** btrees or virtual tables.
+*/
+static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){
+ WhereInfo *pWInfo = pBuilder->pWInfo;
+ WhereClause *pWC;
+ WhereLoop *pNew;
+ WhereTerm *pTerm, *pWCEnd;
+ int rc = SQLITE_OK;
+ int iCur;
+ WhereClause tempWC;
+ WhereLoopBuilder sSubBuild;
+ WhereLoop sBest;
+ struct SrcList_item *pItem;
+
+ pWC = pBuilder->pWC;
+ if( pWInfo->wctrlFlags & WHERE_AND_ONLY ) return SQLITE_OK;
+ pWCEnd = pWC->a + pWC->nTerm;
+ pNew = pBuilder->pNew;
+
+ for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){
+ if( (pTerm->eOperator & WO_OR)!=0
+ && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0
+ ){
+ WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
+ WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
+ WhereTerm *pOrTerm;
+ WhereCost rTotal = 0;
+ WhereCost nRow = 0;
+ Bitmask prereq = mExtra;
+
+ whereLoopInit(&sBest);
+ pItem = pWInfo->pTabList->a + pNew->iTab;
+ iCur = pItem->iCursor;
+ sSubBuild = *pBuilder;
+ sSubBuild.pOrderBy = 0;
+ sSubBuild.pBest = &sBest;
+
+ for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
+ if( (pOrTerm->eOperator & WO_AND)!=0 ){
+ sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
+ }else if( pOrTerm->leftCursor==iCur ){
+ tempWC.pWInfo = pWC->pWInfo;
+ tempWC.pOuter = pWC;
+ tempWC.op = TK_AND;
+ tempWC.nTerm = 1;
+ tempWC.a = pOrTerm;
+ sSubBuild.pWC = &tempWC;
+ }else{
+ continue;
+ }
+ sBest.maskSelf = 0;
+ sBest.rSetup = 0;
+ sBest.rRun = 0;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ if( IsVirtual(pItem->pTab) ){
+ rc = whereLoopAddVirtual(&sSubBuild);
+ }else
+#endif
+ {
+ rc = whereLoopAddBtree(&sSubBuild, mExtra);
+ }
+ /* sBest.maskSelf is always zero if an error occurs */
+ assert( rc==SQLITE_OK || sBest.maskSelf==0 );
+ if( sBest.maskSelf==0 ) break;
+ assert( sBest.rSetup==0 );
+ rTotal = whereCostAdd(rTotal, sBest.rRun);
+ nRow = whereCostAdd(nRow, sBest.nOut);
+ prereq |= sBest.prereq;
+ }
+ assert( pNew->nLSlot>=1 );
+ if( sBest.maskSelf ){
+ pNew->nLTerm = 1;
+ pNew->aLTerm[0] = pTerm;
+ pNew->wsFlags = WHERE_MULTI_OR;
+ pNew->rSetup = 0;
+ /* TUNING: Multiple by 3.5 for the secondary table lookup */
+ pNew->rRun = rTotal + 18; assert( 18==whereCost(7)-whereCost(2) );
+ pNew->nOut = nRow;
+ pNew->prereq = prereq;
+ memset(&pNew->u, 0, sizeof(pNew->u));
+ rc = whereLoopInsert(pBuilder, pNew);
+ }
+ whereLoopClear(pWInfo->pParse->db, &sBest);
+ }
}
+ return rc;
}
+/*
+** Add all WhereLoop objects for all tables
+*/
+static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
+ WhereInfo *pWInfo = pBuilder->pWInfo;
+ Bitmask mExtra = 0;
+ Bitmask mPrior = 0;
+ int iTab;
+ SrcList *pTabList = pWInfo->pTabList;
+ struct SrcList_item *pItem;
+ sqlite3 *db = pWInfo->pParse->db;
+ int nTabList = pWInfo->nLevel;
+ int rc = SQLITE_OK;
+ u8 priorJoinType = 0;
+ WhereLoop *pNew;
+
+ /* Loop over the tables in the join, from left to right */
+ pNew = pBuilder->pNew;
+ whereLoopInit(pNew);
+ for(iTab=0, pItem=pTabList->a; iTab<nTabList; iTab++, pItem++){
+ pNew->iTab = iTab;
+ pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor);
+ if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
+ mExtra = mPrior;
+ }
+ priorJoinType = pItem->jointype;
+ if( IsVirtual(pItem->pTab) ){
+ rc = whereLoopAddVirtual(pBuilder);
+ }else{
+ rc = whereLoopAddBtree(pBuilder, mExtra);
+ }
+ if( rc==SQLITE_OK ){
+ rc = whereLoopAddOr(pBuilder, mExtra);
+ }
+ mPrior |= pNew->maskSelf;
+ if( rc || db->mallocFailed ) break;
+ }
+ whereLoopClear(db, pNew);
+ return rc;
+}
+
+/*
+** Examine a WherePath (with the addition of the extra WhereLoop of the 5th
+** parameters) to see if it outputs rows in the requested ORDER BY
+** (or GROUP BY) without requiring a separate source operation. Return:
+**
+** 0: ORDER BY is not satisfied. Sorting required
+** 1: ORDER BY is satisfied. Omit sorting
+** -1: Unknown at this time
+**
+*/
+static int wherePathSatisfiesOrderBy(
+ WhereInfo *pWInfo, /* The WHERE clause */
+ ExprList *pOrderBy, /* ORDER BY or GROUP BY or DISTINCT clause to check */
+ WherePath *pPath, /* The WherePath to check */
+ u16 wctrlFlags, /* Might contain WHERE_GROUPBY or WHERE_DISTINCTBY */
+ u16 nLoop, /* Number of entries in pPath->aLoop[] */
+ WhereLoop *pLast, /* Add this WhereLoop to the end of pPath->aLoop[] */
+ Bitmask *pRevMask /* OUT: Mask of WhereLoops to run in reverse order */
+){
+ u8 revSet; /* True if rev is known */
+ u8 rev; /* Composite sort order */
+ u8 revIdx; /* Index sort order */
+ u8 isOrderDistinct; /* All prior WhereLoops are order-distinct */
+ u8 distinctColumns; /* True if the loop has UNIQUE NOT NULL columns */
+ u8 isMatch; /* iColumn matches a term of the ORDER BY clause */
+ u16 nColumn; /* Number of columns in pIndex */
+ u16 nOrderBy; /* Number terms in the ORDER BY clause */
+ int iLoop; /* Index of WhereLoop in pPath being processed */
+ int i, j; /* Loop counters */
+ int iCur; /* Cursor number for current WhereLoop */
+ int iColumn; /* A column number within table iCur */
+ WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
+ WhereTerm *pTerm; /* A single term of the WHERE clause */
+ Expr *pOBExpr; /* An expression from the ORDER BY clause */
+ CollSeq *pColl; /* COLLATE function from an ORDER BY clause term */
+ Index *pIndex; /* The index associated with pLoop */
+ sqlite3 *db = pWInfo->pParse->db; /* Database connection */
+ Bitmask obSat = 0; /* Mask of ORDER BY terms satisfied so far */
+ Bitmask obDone; /* Mask of all ORDER BY terms */
+ Bitmask orderDistinctMask; /* Mask of all well-ordered loops */
+ Bitmask ready; /* Mask of inner loops */
+
+ /*
+ ** We say the WhereLoop is "one-row" if it generates no more than one
+ ** row of output. A WhereLoop is one-row if all of the following are true:
+ ** (a) All index columns match with WHERE_COLUMN_EQ.
+ ** (b) The index is unique
+ ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
+ ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
+ **
+ ** We say the WhereLoop is "order-distinct" if the set of columns from
+ ** that WhereLoop that are in the ORDER BY clause are different for every
+ ** row of the WhereLoop. Every one-row WhereLoop is automatically
+ ** order-distinct. A WhereLoop that has no columns in the ORDER BY clause
+ ** is not order-distinct. To be order-distinct is not quite the same as being
+ ** UNIQUE since a UNIQUE column or index can have multiple rows that
+ ** are NULL and NULL values are equivalent for the purpose of order-distinct.
+ ** To be order-distinct, the columns must be UNIQUE and NOT NULL.
+ **
+ ** The rowid for a table is always UNIQUE and NOT NULL so whenever the
+ ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
+ ** automatically order-distinct.
+ */
+
+ assert( pOrderBy!=0 );
+
+ /* Sortability of virtual tables is determined by the xBestIndex method
+ ** of the virtual table itself */
+ if( pLast->wsFlags & WHERE_VIRTUALTABLE ){
+ testcase( nLoop>0 ); /* True when outer loops are one-row and match
+ ** no ORDER BY terms */
+ return pLast->u.vtab.isOrdered;
+ }
+ if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
+
+ nOrderBy = pOrderBy->nExpr;
+ testcase( nOrderBy==BMS-1 );
+ if( nOrderBy>BMS-1 ) return 0; /* Cannot optimize overly large ORDER BYs */
+ isOrderDistinct = 1;
+ obDone = MASKBIT(nOrderBy)-1;
+ orderDistinctMask = 0;
+ ready = 0;
+ for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
+ if( iLoop>0 ) ready |= pLoop->maskSelf;
+ pLoop = iLoop<nLoop ? pPath->aLoop[iLoop] : pLast;
+ assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+ iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
+
+ /* Mark off any ORDER BY term X that is a column in the table of
+ ** the current loop for which there is term in the WHERE
+ ** clause of the form X IS NULL or X=? that reference only outer
+ ** loops.
+ */
+ for(i=0; i<nOrderBy; i++){
+ if( MASKBIT(i) & obSat ) continue;
+ pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+ if( pOBExpr->op!=TK_COLUMN ) continue;
+ if( pOBExpr->iTable!=iCur ) continue;
+ pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+ ~ready, WO_EQ|WO_ISNULL, 0);
+ if( pTerm==0 ) continue;
+ if( (pTerm->eOperator&WO_EQ)!=0 && pOBExpr->iColumn>=0 ){
+ const char *z1, *z2;
+ pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+ if( !pColl ) pColl = db->pDfltColl;
+ z1 = pColl->zName;
+ pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
+ if( !pColl ) pColl = db->pDfltColl;
+ z2 = pColl->zName;
+ if( sqlite3StrICmp(z1, z2)!=0 ) continue;
+ }
+ obSat |= MASKBIT(i);
+ }
+
+ if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
+ if( pLoop->wsFlags & WHERE_IPK ){
+ pIndex = 0;
+ nColumn = 0;
+ }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
+ return 0;
+ }else{
+ nColumn = pIndex->nColumn;
+ isOrderDistinct = pIndex->onError!=OE_None;
+ }
+
+ /* Loop through all columns of the index and deal with the ones
+ ** that are not constrained by == or IN.
+ */
+ rev = revSet = 0;
+ distinctColumns = 0;
+ for(j=0; j<=nColumn; j++){
+ u8 bOnce; /* True to run the ORDER BY search loop */
+
+ /* Skip over == and IS NULL terms */
+ if( j<pLoop->u.btree.nEq
+ && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
+ ){
+ if( i & WO_ISNULL ){
+ testcase( isOrderDistinct );
+ isOrderDistinct = 0;
+ }
+ continue;
+ }
+
+ /* Get the column number in the table (iColumn) and sort order
+ ** (revIdx) for the j-th column of the index.
+ */
+ if( j<nColumn ){
+ /* Normal index columns */
+ iColumn = pIndex->aiColumn[j];
+ revIdx = pIndex->aSortOrder[j];
+ if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
+ }else{
+ /* The ROWID column at the end */
+ assert( j==nColumn );
+ iColumn = -1;
+ revIdx = 0;
+ }
+
+ /* An unconstrained column that might be NULL means that this
+ ** WhereLoop is not well-ordered
+ */
+ if( isOrderDistinct
+ && iColumn>=0
+ && j>=pLoop->u.btree.nEq
+ && pIndex->pTable->aCol[iColumn].notNull==0
+ ){
+ isOrderDistinct = 0;
+ }
+
+ /* Find the ORDER BY term that corresponds to the j-th column
+ ** of the index and and mark that ORDER BY term off
+ */
+ bOnce = 1;
+ isMatch = 0;
+ for(i=0; bOnce && i<nOrderBy; i++){
+ if( MASKBIT(i) & obSat ) continue;
+ pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+ testcase( wctrlFlags & WHERE_GROUPBY );
+ testcase( wctrlFlags & WHERE_DISTINCTBY );
+ if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
+ if( pOBExpr->op!=TK_COLUMN ) continue;
+ if( pOBExpr->iTable!=iCur ) continue;
+ if( pOBExpr->iColumn!=iColumn ) continue;
+ if( iColumn>=0 ){
+ pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+ if( !pColl ) pColl = db->pDfltColl;
+ if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
+ }
+ isMatch = 1;
+ break;
+ }
+ if( isMatch ){
+ if( iColumn<0 ){
+ testcase( distinctColumns==0 );
+ distinctColumns = 1;
+ }
+ obSat |= MASKBIT(i);
+ if( (pWInfo->wctrlFlags & WHERE_GROUPBY)==0 ){
+ /* Make sure the sort order is compatible in an ORDER BY clause.
+ ** Sort order is irrelevant for a GROUP BY clause. */
+ if( revSet ){
+ if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) return 0;
+ }else{
+ rev = revIdx ^ pOrderBy->a[i].sortOrder;
+ if( rev ) *pRevMask |= MASKBIT(iLoop);
+ revSet = 1;
+ }
+ }
+ }else{
+ /* No match found */
+ if( j==0 || j<nColumn ){
+ testcase( isOrderDistinct!=0 );
+ isOrderDistinct = 0;
+ }
+ break;
+ }
+ } /* end Loop over all index columns */
+ if( distinctColumns ){
+ testcase( isOrderDistinct==0 );
+ isOrderDistinct = 1;
+ }
+ } /* end-if not one-row */
+
+ /* Mark off any other ORDER BY terms that reference pLoop */
+ if( isOrderDistinct ){
+ orderDistinctMask |= pLoop->maskSelf;
+ for(i=0; i<nOrderBy; i++){
+ Expr *p;
+ if( MASKBIT(i) & obSat ) continue;
+ p = pOrderBy->a[i].pExpr;
+ if( (exprTableUsage(&pWInfo->sMaskSet, p)&~orderDistinctMask)==0 ){
+ obSat |= MASKBIT(i);
+ }
+ }
+ }
+ } /* End the loop over all WhereLoops from outer-most down to inner-most */
+ if( obSat==obDone ) return 1;
+ if( !isOrderDistinct ) return 0;
+ return -1;
+}
+
+#ifdef WHERETRACE_ENABLED
+/* For debugging use only: */
+static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
+ static char zName[65];
+ int i;
+ for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; }
+ if( pLast ) zName[i++] = pLast->cId;
+ zName[i] = 0;
+ return zName;
+}
+#endif
+
+
+/*
+** Given the list of WhereLoop objects on pWInfo->pLoops, this routine
+** attempts to find the lowest cost path that visits each WhereLoop
+** once. This path is then loaded into the pWInfo->a[].pWLoop fields.
+**
+** Assume that the total number of output rows that will need to be sorted
+** will be nRowEst (in the 10*log2 representation). Or, ignore sorting
+** costs if nRowEst==0.
+**
+** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation
+** error occurs.
+*/
+static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
+ int mxChoice; /* Maximum number of simultaneous paths tracked */
+ int nLoop; /* Number of terms in the join */
+ Parse *pParse; /* Parsing context */
+ sqlite3 *db; /* The database connection */
+ int iLoop; /* Loop counter over the terms of the join */
+ int ii, jj; /* Loop counters */
+ WhereCost rCost; /* Cost of a path */
+ WhereCost mxCost = 0; /* Maximum cost of a set of paths */
+ WhereCost rSortCost; /* Cost to do a sort */
+ int nTo, nFrom; /* Number of valid entries in aTo[] and aFrom[] */
+ WherePath *aFrom; /* All nFrom paths at the previous level */
+ WherePath *aTo; /* The nTo best paths at the current level */
+ WherePath *pFrom; /* An element of aFrom[] that we are working on */
+ WherePath *pTo; /* An element of aTo[] that we are working on */
+ WhereLoop *pWLoop; /* One of the WhereLoop objects */
+ WhereLoop **pX; /* Used to divy up the pSpace memory */
+ char *pSpace; /* Temporary memory used by this routine */
+
+ pParse = pWInfo->pParse;
+ db = pParse->db;
+ nLoop = pWInfo->nLevel;
+ /* TUNING: For simple queries, only the best path is tracked.
+ ** For 2-way joins, the 5 best paths are followed.
+ ** For joins of 3 or more tables, track the 10 best paths */
+ mxChoice = (nLoop==1) ? 1 : (nLoop==2 ? 5 : 10);
+ assert( nLoop<=pWInfo->pTabList->nSrc );
+ WHERETRACE(0x002, ("---- begin solver\n"));
+
+ /* Allocate and initialize space for aTo and aFrom */
+ ii = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
+ pSpace = sqlite3DbMallocRaw(db, ii);
+ if( pSpace==0 ) return SQLITE_NOMEM;
+ aTo = (WherePath*)pSpace;
+ aFrom = aTo+mxChoice;
+ memset(aFrom, 0, sizeof(aFrom[0]));
+ pX = (WhereLoop**)(aFrom+mxChoice);
+ for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
+ pFrom->aLoop = pX;
+ }
+
+ /* Seed the search with a single WherePath containing zero WhereLoops.
+ **
+ ** TUNING: Do not let the number of iterations go above 25. If the cost
+ ** of computing an automatic index is not paid back within the first 25
+ ** rows, then do not use the automatic index. */
+ aFrom[0].nRow = MIN(pParse->nQueryLoop, 46); assert( 46==whereCost(25) );
+ nFrom = 1;
+
+ /* Precompute the cost of sorting the final result set, if the caller
+ ** to sqlite3WhereBegin() was concerned about sorting */
+ rSortCost = 0;
+ if( pWInfo->pOrderBy==0 || nRowEst==0 ){
+ aFrom[0].isOrderedValid = 1;
+ }else{
+ /* TUNING: Estimated cost of sorting is N*log2(N) where N is the
+ ** number of output rows. */
+ rSortCost = nRowEst + estLog(nRowEst);
+ WHERETRACE(0x002,("---- sort cost=%-3d\n", rSortCost));
+ }
+
+ /* Compute successively longer WherePaths using the previous generation
+ ** of WherePaths as the basis for the next. Keep track of the mxChoice
+ ** best paths at each generation */
+ for(iLoop=0; iLoop<nLoop; iLoop++){
+ nTo = 0;
+ for(ii=0, pFrom=aFrom; ii<nFrom; ii++, pFrom++){
+ for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
+ Bitmask maskNew;
+ Bitmask revMask = 0;
+ u8 isOrderedValid = pFrom->isOrderedValid;
+ u8 isOrdered = pFrom->isOrdered;
+ if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;
+ if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;
+ /* At this point, pWLoop is a candidate to be the next loop.
+ ** Compute its cost */
+ rCost = whereCostAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
+ rCost = whereCostAdd(rCost, pFrom->rCost);
+ maskNew = pFrom->maskLoop | pWLoop->maskSelf;
+ if( !isOrderedValid ){
+ switch( wherePathSatisfiesOrderBy(pWInfo,
+ pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,
+ iLoop, pWLoop, &revMask) ){
+ case 1: /* Yes. pFrom+pWLoop does satisfy the ORDER BY clause */
+ isOrdered = 1;
+ isOrderedValid = 1;
+ break;
+ case 0: /* No. pFrom+pWLoop will require a separate sort */
+ isOrdered = 0;
+ isOrderedValid = 1;
+ rCost = whereCostAdd(rCost, rSortCost);
+ break;
+ default: /* Cannot tell yet. Try again on the next iteration */
+ break;
+ }
+ }else{
+ revMask = pFrom->revLoop;
+ }
+ /* Check to see if pWLoop should be added to the mxChoice best so far */
+ for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){
+ if( pTo->maskLoop==maskNew && pTo->isOrderedValid==isOrderedValid ){
+ testcase( jj==nTo-1 );
+ break;
+ }
+ }
+ if( jj>=nTo ){
+ if( nTo>=mxChoice && rCost>=mxCost ){
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace&0x4 ){
+ sqlite3DebugPrintf("Skip %s cost=%3d order=%c\n",
+ wherePathName(pFrom, iLoop, pWLoop), rCost,
+ isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+ }
+#endif
+ continue;
+ }
+ /* Add a new Path to the aTo[] set */
+ if( nTo<mxChoice ){
+ /* Increase the size of the aTo set by one */
+ jj = nTo++;
+ }else{
+ /* New path replaces the prior worst to keep count below mxChoice */
+ for(jj=nTo-1; aTo[jj].rCost<mxCost; jj--){ assert(jj>0); }
+ }
+ pTo = &aTo[jj];
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace&0x4 ){
+ sqlite3DebugPrintf("New %s cost=%-3d order=%c\n",
+ wherePathName(pFrom, iLoop, pWLoop), rCost,
+ isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+ }
+#endif
+ }else{
+ if( pTo->rCost<=rCost ){
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace&0x4 ){
+ sqlite3DebugPrintf(
+ "Skip %s cost=%-3d order=%c",
+ wherePathName(pFrom, iLoop, pWLoop), rCost,
+ isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+ sqlite3DebugPrintf(" vs %s cost=%-3d order=%c\n",
+ wherePathName(pTo, iLoop+1, 0), pTo->rCost,
+ pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
+ }
+#endif
+ testcase( pTo->rCost==rCost );
+ continue;
+ }
+ testcase( pTo->rCost==rCost+1 );
+ /* A new and better score for a previously created equivalent path */
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace&0x4 ){
+ sqlite3DebugPrintf(
+ "Update %s cost=%-3d order=%c",
+ wherePathName(pFrom, iLoop, pWLoop), rCost,
+ isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+ sqlite3DebugPrintf(" was %s cost=%-3d order=%c\n",
+ wherePathName(pTo, iLoop+1, 0), pTo->rCost,
+ pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
+ }
+#endif
+ }
+ /* pWLoop is a winner. Add it to the set of best so far */
+ pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
+ pTo->revLoop = revMask;
+ pTo->nRow = pFrom->nRow + pWLoop->nOut;
+ pTo->rCost = rCost;
+ pTo->isOrderedValid = isOrderedValid;
+ pTo->isOrdered = isOrdered;
+ memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
+ pTo->aLoop[iLoop] = pWLoop;
+ if( nTo>=mxChoice ){
+ mxCost = aTo[0].rCost;
+ for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){
+ if( pTo->rCost>mxCost ) mxCost = pTo->rCost;
+ }
+ }
+ }
+ }
+
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace>=2 ){
+ sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
+ for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
+ sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",
+ wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+ pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
+ if( pTo->isOrderedValid && pTo->isOrdered ){
+ sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
+ }else{
+ sqlite3DebugPrintf("\n");
+ }
+ }
+ }
+#endif
+
+ /* Swap the roles of aFrom and aTo for the next generation */
+ pFrom = aTo;
+ aTo = aFrom;
+ aFrom = pFrom;
+ nFrom = nTo;
+ }
+
+ if( nFrom==0 ){
+ sqlite3ErrorMsg(pParse, "no query solution");
+ sqlite3DbFree(db, pSpace);
+ return SQLITE_ERROR;
+ }
+
+ /* Find the lowest cost path. pFrom will be left pointing to that path */
+ pFrom = aFrom;
+ assert( nFrom==1 );
+#if 0 /* The following is needed if nFrom is ever more than 1 */
+ for(ii=1; ii<nFrom; ii++){
+ if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
+ }
+#endif
+ assert( pWInfo->nLevel==nLoop );
+ /* Load the lowest cost path into pWInfo */
+ for(iLoop=0; iLoop<nLoop; iLoop++){
+ WhereLevel *pLevel = pWInfo->a + iLoop;
+ pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];
+ pLevel->iFrom = pWLoop->iTab;
+ pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
+ }
+ if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
+ && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
+ && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
+ && nRowEst
+ ){
+ Bitmask notUsed;
+ int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom,
+ WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], &notUsed);
+ if( rc==1 ) pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+ }
+ if( pFrom->isOrdered ){
+ if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
+ pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+ }else{
+ pWInfo->bOBSat = 1;
+ pWInfo->revMask = pFrom->revLoop;
+ }
+ }
+ pWInfo->nRowOut = pFrom->nRow;
+
+ /* Free temporary memory and return success */
+ sqlite3DbFree(db, pSpace);
+ return SQLITE_OK;
+}
+
+/*
+** Most queries use only a single table (they are not joins) and have
+** simple == constraints against indexed fields. This routine attempts
+** to plan those simple cases using much less ceremony than the
+** general-purpose query planner, and thereby yield faster sqlite3_prepare()
+** times for the common case.
+**
+** Return non-zero on success, if this query can be handled by this
+** no-frills query planner. Return zero if this query needs the
+** general-purpose query planner.
+*/
+static int whereShortCut(WhereLoopBuilder *pBuilder){
+ WhereInfo *pWInfo;
+ struct SrcList_item *pItem;
+ WhereClause *pWC;
+ WhereTerm *pTerm;
+ WhereLoop *pLoop;
+ int iCur;
+ int j;
+ Table *pTab;
+ Index *pIdx;
+
+ pWInfo = pBuilder->pWInfo;
+ if( pWInfo->wctrlFlags & WHERE_FORCE_TABLE ) return 0;
+ assert( pWInfo->pTabList->nSrc>=1 );
+ pItem = pWInfo->pTabList->a;
+ pTab = pItem->pTab;
+ if( IsVirtual(pTab) ) return 0;
+ if( pItem->zIndex ) return 0;
+ iCur = pItem->iCursor;
+ pWC = &pWInfo->sWC;
+ pLoop = pBuilder->pNew;
+ pLoop->wsFlags = 0;
+ pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 0);
+ if( pTerm ){
+ pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
+ pLoop->aLTerm[0] = pTerm;
+ pLoop->nLTerm = 1;
+ pLoop->u.btree.nEq = 1;
+ /* TUNING: Cost of a rowid lookup is 10 */
+ pLoop->rRun = 33; /* 33==whereCost(10) */
+ }else{
+ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+ if( pIdx->onError==OE_None ) continue;
+ for(j=0; j<pIdx->nColumn; j++){
+ pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
+ if( pTerm==0 ) break;
+ whereLoopResize(pWInfo->pParse->db, pLoop, j);
+ pLoop->aLTerm[j] = pTerm;
+ }
+ if( j!=pIdx->nColumn ) continue;
+ pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
+ if( (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
+ pLoop->wsFlags |= WHERE_IDX_ONLY;
+ }
+ pLoop->nLTerm = j;
+ pLoop->u.btree.nEq = j;
+ pLoop->u.btree.pIndex = pIdx;
+ /* TUNING: Cost of a unique index lookup is 15 */
+ pLoop->rRun = 39; /* 39==whereCost(15) */
+ break;
+ }
+ }
+ if( pLoop->wsFlags ){
+ pLoop->nOut = (WhereCost)1;
+ pWInfo->a[0].pWLoop = pLoop;
+ pLoop->maskSelf = getMask(&pWInfo->sMaskSet, iCur);
+ pWInfo->a[0].iTabCur = iCur;
+ pWInfo->nRowOut = 1;
+ if( pWInfo->pOrderBy ) pWInfo->bOBSat = 1;
+ if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
+ pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+ }
+#ifdef SQLITE_DEBUG
+ pLoop->cId = '0';
+#endif
+ return 1;
+ }
+ return 0;
+}
/*
** Generate the beginning of the loop used for WHERE clause processing.
@@ -5040,22 +5554,13 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
** pOrderBy is a pointer to the ORDER BY clause of a SELECT statement,
** if there is one. If there is no ORDER BY clause or if this routine
** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
-**
-** If an index can be used so that the natural output order of the table
-** scan is correct for the ORDER BY clause, then that index is used and
-** the returned WhereInfo.nOBSat field is set to pOrderBy->nExpr. This
-** is an optimization that prevents an unnecessary sort of the result set
-** if an index appropriate for the ORDER BY clause already exists.
-**
-** If the where clause loops cannot be arranged to provide the correct
-** output order, then WhereInfo.nOBSat is 0.
*/
WhereInfo *sqlite3WhereBegin(
Parse *pParse, /* The parser context */
- SrcList *pTabList, /* A list of all tables to be scanned */
+ SrcList *pTabList, /* FROM clause: A list of all tables to be scanned */
Expr *pWhere, /* The WHERE clause */
ExprList *pOrderBy, /* An ORDER BY clause, or NULL */
- ExprList *pDistinct, /* The select-list for DISTINCT queries - or NULL */
+ ExprList *pResultSet, /* Result set of the query */
u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */
int iIdxCur /* If WHERE_ONETABLE_ONLY is set, index cursor number */
){
@@ -5064,18 +5569,25 @@ WhereInfo *sqlite3WhereBegin(
WhereInfo *pWInfo; /* Will become the return value of this function */
Vdbe *v = pParse->pVdbe; /* The virtual database engine */
Bitmask notReady; /* Cursors that are not yet positioned */
- WhereBestIdx sWBI; /* Best index search context */
+ WhereLoopBuilder sWLB; /* The WhereLoop builder */
WhereMaskSet *pMaskSet; /* The expression mask set */
WhereLevel *pLevel; /* A single level in pWInfo->a[] */
- int iFrom; /* First unused FROM clause element */
- int andFlags; /* AND-ed combination of all pWC->a[].wtFlags */
+ WhereLoop *pLoop; /* Pointer to a single WhereLoop object */
int ii; /* Loop counter */
sqlite3 *db; /* Database connection */
+ int rc; /* Return code */
/* Variable initialization */
- memset(&sWBI, 0, sizeof(sWBI));
- sWBI.pParse = pParse;
+ db = pParse->db;
+ memset(&sWLB, 0, sizeof(sWLB));
+ sWLB.pOrderBy = pOrderBy;
+
+ /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
+ ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
+ if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
+ wctrlFlags &= ~WHERE_WANT_DISTINCT;
+ }
/* The number of tables in the FROM clause is limited by the number of
** bits in a Bitmask
@@ -5100,13 +5612,8 @@ WhereInfo *sqlite3WhereBegin(
** field (type Bitmask) it must be aligned on an 8-byte boundary on
** some architectures. Hence the ROUND8() below.
*/
- db = pParse->db;
nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
- pWInfo = sqlite3DbMallocZero(db,
- nByteWInfo +
- sizeof(WhereClause) +
- sizeof(WhereMaskSet)
- );
+ pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop));
if( db->mallocFailed ){
sqlite3DbFree(db, pWInfo);
pWInfo = 0;
@@ -5115,24 +5622,27 @@ WhereInfo *sqlite3WhereBegin(
pWInfo->nLevel = nTabList;
pWInfo->pParse = pParse;
pWInfo->pTabList = pTabList;
+ pWInfo->pOrderBy = pOrderBy;
+ pWInfo->pResultSet = pResultSet;
pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
- pWInfo->pWC = sWBI.pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo];
pWInfo->wctrlFlags = wctrlFlags;
pWInfo->savedNQueryLoop = pParse->nQueryLoop;
- pMaskSet = (WhereMaskSet*)&sWBI.pWC[1];
- sWBI.aLevel = pWInfo->a;
-
- /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
- ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
- if( OptimizationDisabled(db, SQLITE_DistinctOpt) ) pDistinct = 0;
+ pMaskSet = &pWInfo->sMaskSet;
+ sWLB.pWInfo = pWInfo;
+ sWLB.pWC = &pWInfo->sWC;
+ sWLB.pNew = (WhereLoop*)&pWInfo->a[nTabList];
+ whereLoopInit(sWLB.pNew);
+#ifdef SQLITE_DEBUG
+ sWLB.pNew->cId = '*';
+#endif
/* Split the WHERE clause into separate subexpressions where each
** subexpression is separated by an AND operator.
*/
initMaskSet(pMaskSet);
- whereClauseInit(sWBI.pWC, pParse, pMaskSet, wctrlFlags);
+ whereClauseInit(&pWInfo->sWC, pWInfo);
sqlite3ExprCodeConstants(pParse, pWhere);
- whereSplit(sWBI.pWC, pWhere, TK_AND); /* IMP: R-15842-53296 */
+ whereSplit(&pWInfo->sWC, pWhere, TK_AND); /* IMP: R-15842-53296 */
/* Special case: a WHERE clause that is constant. Evaluate the
** expression and either jump over all of the code or fall thru.
@@ -5142,6 +5652,15 @@ WhereInfo *sqlite3WhereBegin(
pWhere = 0;
}
+ /* Special case: No FROM clause
+ */
+ if( nTabList==0 ){
+ if( pOrderBy ) pWInfo->bOBSat = 1;
+ if( wctrlFlags & WHERE_WANT_DISTINCT ){
+ pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+ }
+ }
+
/* Assign a bit from the bitmask to every term in the FROM clause.
**
** When assigning bitmask values to FROM clause cursors, it must be
@@ -5177,288 +5696,121 @@ WhereInfo *sqlite3WhereBegin(
** want to analyze these virtual terms, so start analyzing at the end
** and work forward so that the added virtual terms are never processed.
*/
- exprAnalyzeAll(pTabList, sWBI.pWC);
+ exprAnalyzeAll(pTabList, &pWInfo->sWC);
if( db->mallocFailed ){
goto whereBeginError;
}
- /* Check if the DISTINCT qualifier, if there is one, is redundant.
- ** If it is, then set pDistinct to NULL and WhereInfo.eDistinct to
- ** WHERE_DISTINCT_UNIQUE to tell the caller to ignore the DISTINCT.
+ /* If the ORDER BY (or GROUP BY) clause contains references to general
+ ** expressions, then we won't be able to satisfy it using indices, so
+ ** go ahead and disable it now.
*/
- if( pDistinct && isDistinctRedundant(pParse, pTabList, sWBI.pWC, pDistinct) ){
- pDistinct = 0;
- pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+ if( pOrderBy && (wctrlFlags & WHERE_WANT_DISTINCT)!=0 ){
+ for(ii=0; ii<pOrderBy->nExpr; ii++){
+ Expr *pExpr = sqlite3ExprSkipCollate(pOrderBy->a[ii].pExpr);
+ if( pExpr->op!=TK_COLUMN ){
+ pWInfo->pOrderBy = pOrderBy = 0;
+ break;
+ }else if( pExpr->iColumn<0 ){
+ break;
+ }
+ }
}
- /* Chose the best index to use for each table in the FROM clause.
- **
- ** This loop fills in the following fields:
- **
- ** pWInfo->a[].pIdx The index to use for this level of the loop.
- ** pWInfo->a[].wsFlags WHERE_xxx flags associated with pIdx
- ** pWInfo->a[].nEq The number of == and IN constraints
- ** pWInfo->a[].iFrom Which term of the FROM clause is being coded
- ** pWInfo->a[].iTabCur The VDBE cursor for the database table
- ** pWInfo->a[].iIdxCur The VDBE cursor for the index
- ** pWInfo->a[].pTerm When wsFlags==WO_OR, the OR-clause term
- **
- ** This loop also figures out the nesting order of tables in the FROM
- ** clause.
- */
- sWBI.notValid = ~(Bitmask)0;
- sWBI.pOrderBy = pOrderBy;
- sWBI.n = nTabList;
- sWBI.pDistinct = pDistinct;
- andFlags = ~0;
- WHERETRACE(("*** Optimizer Start ***\n"));
- for(sWBI.i=iFrom=0, pLevel=pWInfo->a; sWBI.i<nTabList; sWBI.i++, pLevel++){
- WhereCost bestPlan; /* Most efficient plan seen so far */
- Index *pIdx; /* Index for FROM table at pTabItem */
- int j; /* For looping over FROM tables */
- int bestJ = -1; /* The value of j */
- Bitmask m; /* Bitmask value for j or bestJ */
- int isOptimal; /* Iterator for optimal/non-optimal search */
- int ckOptimal; /* Do the optimal scan check */
- int nUnconstrained; /* Number tables without INDEXED BY */
- Bitmask notIndexed; /* Mask of tables that cannot use an index */
-
- memset(&bestPlan, 0, sizeof(bestPlan));
- bestPlan.rCost = SQLITE_BIG_DBL;
- WHERETRACE(("*** Begin search for loop %d ***\n", sWBI.i));
-
- /* Loop through the remaining entries in the FROM clause to find the
- ** next nested loop. The loop tests all FROM clause entries
- ** either once or twice.
- **
- ** The first test is always performed if there are two or more entries
- ** remaining and never performed if there is only one FROM clause entry
- ** to choose from. The first test looks for an "optimal" scan. In
- ** this context an optimal scan is one that uses the same strategy
- ** for the given FROM clause entry as would be selected if the entry
- ** were used as the innermost nested loop. In other words, a table
- ** is chosen such that the cost of running that table cannot be reduced
- ** by waiting for other tables to run first. This "optimal" test works
- ** by first assuming that the FROM clause is on the inner loop and finding
- ** its query plan, then checking to see if that query plan uses any
- ** other FROM clause terms that are sWBI.notValid. If no notValid terms
- ** are used then the "optimal" query plan works.
- **
- ** Note that the WhereCost.nRow parameter for an optimal scan might
- ** not be as small as it would be if the table really were the innermost
- ** join. The nRow value can be reduced by WHERE clause constraints
- ** that do not use indices. But this nRow reduction only happens if the
- ** table really is the innermost join.
- **
- ** The second loop iteration is only performed if no optimal scan
- ** strategies were found by the first iteration. This second iteration
- ** is used to search for the lowest cost scan overall.
- **
- ** Without the optimal scan step (the first iteration) a suboptimal
- ** plan might be chosen for queries like this:
- **
- ** CREATE TABLE t1(a, b);
- ** CREATE TABLE t2(c, d);
- ** SELECT * FROM t2, t1 WHERE t2.rowid = t1.a;
- **
- ** The best strategy is to iterate through table t1 first. However it
- ** is not possible to determine this with a simple greedy algorithm.
- ** Since the cost of a linear scan through table t2 is the same
- ** as the cost of a linear scan through table t1, a simple greedy
- ** algorithm may choose to use t2 for the outer loop, which is a much
- ** costlier approach.
- */
- nUnconstrained = 0;
- notIndexed = 0;
-
- /* The optimal scan check only occurs if there are two or more tables
- ** available to be reordered */
- if( iFrom==nTabList-1 ){
- ckOptimal = 0; /* Common case of just one table in the FROM clause */
- }else{
- ckOptimal = -1;
- for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){
- m = getMask(pMaskSet, sWBI.pSrc->iCursor);
- if( (m & sWBI.notValid)==0 ){
- if( j==iFrom ) iFrom++;
- continue;
- }
- if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ) break;
- if( ++ckOptimal ) break;
- if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break;
- }
+ if( wctrlFlags & WHERE_WANT_DISTINCT ){
+ if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
+ /* The DISTINCT marking is pointless. Ignore it. */
+ pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+ }else if( pOrderBy==0 ){
+ /* Try to ORDER BY the result set to make distinct processing easier */
+ pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
+ pWInfo->pOrderBy = pResultSet;
}
- assert( ckOptimal==0 || ckOptimal==1 );
+ }
- for(isOptimal=ckOptimal; isOptimal>=0 && bestJ<0; isOptimal--){
- for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){
- if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ){
- /* This break and one like it in the ckOptimal computation loop
- ** above prevent table reordering across LEFT and CROSS JOINs.
- ** The LEFT JOIN case is necessary for correctness. The prohibition
- ** against reordering across a CROSS JOIN is an SQLite feature that
- ** allows the developer to control table reordering */
- break;
- }
- m = getMask(pMaskSet, sWBI.pSrc->iCursor);
- if( (m & sWBI.notValid)==0 ){
- assert( j>iFrom );
- continue;
- }
- sWBI.notReady = (isOptimal ? m : sWBI.notValid);
- if( sWBI.pSrc->pIndex==0 ) nUnconstrained++;
+ /* Construct the WhereLoop objects */
+ WHERETRACE(0xffff,("*** Optimizer Start ***\n"));
+ if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
+ rc = whereLoopAddAll(&sWLB);
+ if( rc ) goto whereBeginError;
- WHERETRACE((" === trying table %d (%s) with isOptimal=%d ===\n",
- j, sWBI.pSrc->pTab->zName, isOptimal));
- assert( sWBI.pSrc->pTab );
-#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( IsVirtual(sWBI.pSrc->pTab) ){
- sWBI.ppIdxInfo = &pWInfo->a[j].pIdxInfo;
- bestVirtualIndex(&sWBI);
- }else
-#endif
- {
- bestBtreeIndex(&sWBI);
- }
- assert( isOptimal || (sWBI.cost.used&sWBI.notValid)==0 );
-
- /* If an INDEXED BY clause is present, then the plan must use that
- ** index if it uses any index at all */
- assert( sWBI.pSrc->pIndex==0
- || (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0
- || sWBI.cost.plan.u.pIdx==sWBI.pSrc->pIndex );
-
- if( isOptimal && (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){
- notIndexed |= m;
- }
- if( isOptimal ){
- pWInfo->a[j].rOptCost = sWBI.cost.rCost;
- }else if( ckOptimal ){
- /* If two or more tables have nearly the same outer loop cost, but
- ** very different inner loop (optimal) cost, we want to choose
- ** for the outer loop that table which benefits the least from
- ** being in the inner loop. The following code scales the
- ** outer loop cost estimate to accomplish that. */
- WHERETRACE((" scaling cost from %.1f to %.1f\n",
- sWBI.cost.rCost,
- sWBI.cost.rCost/pWInfo->a[j].rOptCost));
- sWBI.cost.rCost /= pWInfo->a[j].rOptCost;
- }
-
- /* Conditions under which this table becomes the best so far:
- **
- ** (1) The table must not depend on other tables that have not
- ** yet run. (In other words, it must not depend on tables
- ** in inner loops.)
- **
- ** (2) (This rule was removed on 2012-11-09. The scaling of the
- ** cost using the optimal scan cost made this rule obsolete.)
- **
- ** (3) All tables have an INDEXED BY clause or this table lacks an
- ** INDEXED BY clause or this table uses the specific
- ** index specified by its INDEXED BY clause. This rule ensures
- ** that a best-so-far is always selected even if an impossible
- ** combination of INDEXED BY clauses are given. The error
- ** will be detected and relayed back to the application later.
- ** The NEVER() comes about because rule (2) above prevents
- ** An indexable full-table-scan from reaching rule (3).
- **
- ** (4) The plan cost must be lower than prior plans, where "cost"
- ** is defined by the compareCost() function above.
- */
- if( (sWBI.cost.used&sWBI.notValid)==0 /* (1) */
- && (nUnconstrained==0 || sWBI.pSrc->pIndex==0 /* (3) */
- || NEVER((sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0))
- && (bestJ<0 || compareCost(&sWBI.cost, &bestPlan)) /* (4) */
- ){
- WHERETRACE((" === table %d (%s) is best so far\n"
- " cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=%08x\n",
- j, sWBI.pSrc->pTab->zName,
- sWBI.cost.rCost, sWBI.cost.plan.nRow,
- sWBI.cost.plan.nOBSat, sWBI.cost.plan.wsFlags));
- bestPlan = sWBI.cost;
- bestJ = j;
- }
-
- /* In a join like "w JOIN x LEFT JOIN y JOIN z" make sure that
- ** table y (and not table z) is always the next inner loop inside
- ** of table x. */
- if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break;
+ /* Display all of the WhereLoop objects if wheretrace is enabled */
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace ){
+ WhereLoop *p;
+ int i;
+ static char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
+ "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
+ for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
+ p->cId = zLabel[i%sizeof(zLabel)];
+ whereLoopPrint(p, pTabList);
}
}
- assert( bestJ>=0 );
- assert( sWBI.notValid & getMask(pMaskSet, pTabList->a[bestJ].iCursor) );
- assert( bestJ==iFrom || (pTabList->a[iFrom].jointype & JT_LEFT)==0 );
- testcase( bestJ>iFrom && (pTabList->a[iFrom].jointype & JT_CROSS)!=0 );
- testcase( bestJ>iFrom && bestJ<nTabList-1
- && (pTabList->a[bestJ+1].jointype & JT_LEFT)!=0 );
- WHERETRACE(("*** Optimizer selects table %d (%s) for loop %d with:\n"
- " cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=0x%08x\n",
- bestJ, pTabList->a[bestJ].pTab->zName,
- pLevel-pWInfo->a, bestPlan.rCost, bestPlan.plan.nRow,
- bestPlan.plan.nOBSat, bestPlan.plan.wsFlags));
- if( (bestPlan.plan.wsFlags & WHERE_DISTINCT)!=0 ){
- assert( pWInfo->eDistinct==0 );
- pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+#endif
+
+ wherePathSolver(pWInfo, 0);
+ if( db->mallocFailed ) goto whereBeginError;
+ if( pWInfo->pOrderBy ){
+ wherePathSolver(pWInfo, pWInfo->nRowOut+1);
+ if( db->mallocFailed ) goto whereBeginError;
}
- andFlags &= bestPlan.plan.wsFlags;
- pLevel->plan = bestPlan.plan;
- pLevel->iTabCur = pTabList->a[bestJ].iCursor;
- testcase( bestPlan.plan.wsFlags & WHERE_INDEXED );
- testcase( bestPlan.plan.wsFlags & WHERE_TEMP_INDEX );
- if( bestPlan.plan.wsFlags & (WHERE_INDEXED|WHERE_TEMP_INDEX) ){
- if( (wctrlFlags & WHERE_ONETABLE_ONLY)
- && (bestPlan.plan.wsFlags & WHERE_TEMP_INDEX)==0
- ){
- pLevel->iIdxCur = iIdxCur;
- }else{
- pLevel->iIdxCur = pParse->nTab++;
+ }
+ if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){
+ pWInfo->revMask = (Bitmask)(-1);
+ }
+ if( pParse->nErr || NEVER(db->mallocFailed) ){
+ goto whereBeginError;
+ }
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace ){
+ int ii;
+ sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
+ if( pWInfo->bOBSat ){
+ sqlite3DebugPrintf(" ORDERBY=0x%llx", pWInfo->revMask);
+ }
+ switch( pWInfo->eDistinct ){
+ case WHERE_DISTINCT_UNIQUE: {
+ sqlite3DebugPrintf(" DISTINCT=unique");
+ break;
+ }
+ case WHERE_DISTINCT_ORDERED: {
+ sqlite3DebugPrintf(" DISTINCT=ordered");
+ break;
+ }
+ case WHERE_DISTINCT_UNORDERED: {
+ sqlite3DebugPrintf(" DISTINCT=unordered");
+ break;
}
- }else{
- pLevel->iIdxCur = -1;
}
- sWBI.notValid &= ~getMask(pMaskSet, pTabList->a[bestJ].iCursor);
- pLevel->iFrom = (u8)bestJ;
- if( bestPlan.plan.nRow>=(double)1 ){
- pParse->nQueryLoop *= bestPlan.plan.nRow;
+ sqlite3DebugPrintf("\n");
+ for(ii=0; ii<pWInfo->nLevel; ii++){
+ whereLoopPrint(pWInfo->a[ii].pWLoop, pTabList);
}
-
- /* Check that if the table scanned by this loop iteration had an
- ** INDEXED BY clause attached to it, that the named index is being
- ** used for the scan. If not, then query compilation has failed.
- ** Return an error.
- */
- pIdx = pTabList->a[bestJ].pIndex;
- if( pIdx ){
- if( (bestPlan.plan.wsFlags & WHERE_INDEXED)==0 ){
- sqlite3ErrorMsg(pParse, "cannot use index: %s", pIdx->zName);
- goto whereBeginError;
- }else{
- /* If an INDEXED BY clause is used, the bestIndex() function is
- ** guaranteed to find the index specified in the INDEXED BY clause
- ** if it find an index at all. */
- assert( bestPlan.plan.u.pIdx==pIdx );
+ }
+#endif
+ /* Attempt to omit tables from the join that do not effect the result */
+ if( pWInfo->nLevel>=2
+ && pResultSet!=0
+ && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
+ ){
+ Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
+ if( pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, pOrderBy);
+ while( pWInfo->nLevel>=2 ){
+ pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
+ if( (pWInfo->pTabList->a[pLoop->iTab].jointype & JT_LEFT)==0 ) break;
+ if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
+ && (pLoop->wsFlags & WHERE_ONEROW)==0
+ ){
+ break;
}
+ if( (tabUsed & pLoop->maskSelf)!=0 ) break;
+ WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));
+ pWInfo->nLevel--;
+ nTabList--;
}
}
- WHERETRACE(("*** Optimizer Finished ***\n"));
- if( pParse->nErr || db->mallocFailed ){
- goto whereBeginError;
- }
- if( nTabList ){
- pLevel--;
- pWInfo->nOBSat = pLevel->plan.nOBSat;
- }else{
- pWInfo->nOBSat = 0;
- }
-
- /* If the total query only selects a single row, then the ORDER BY
- ** clause is irrelevant.
- */
- if( (andFlags & WHERE_UNIQUE)!=0 && pOrderBy ){
- assert( nTabList==0 || (pLevel->plan.wsFlags & WHERE_ALL_UNIQUE)!=0 );
- pWInfo->nOBSat = pOrderBy->nExpr;
- }
+ WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
+ pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
/* If the caller is an UPDATE or DELETE statement that is requesting
** to use a one-pass algorithm, determine if this is appropriate.
@@ -5466,9 +5818,10 @@ WhereInfo *sqlite3WhereBegin(
** the statement to update a single row.
*/
assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
- if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 && (andFlags & WHERE_UNIQUE)!=0 ){
+ if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0
+ && (pWInfo->a[0].pWLoop->wsFlags & WHERE_ONEROW)!=0 ){
pWInfo->okOnePass = 1;
- pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY;
+ pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY;
}
/* Open all tables in the pTabList and any indices selected for
@@ -5476,21 +5829,21 @@ WhereInfo *sqlite3WhereBegin(
*/
sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
notReady = ~(Bitmask)0;
- pWInfo->nRowOut = (double)1;
for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
Table *pTab; /* Table to open */
int iDb; /* Index of database containing table/index */
struct SrcList_item *pTabItem;
+ WhereLoop *pLoop;
pTabItem = &pTabList->a[pLevel->iFrom];
pTab = pTabItem->pTab;
- pWInfo->nRowOut *= pLevel->plan.nRow;
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+ pLoop = pLevel->pWLoop;
if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){
/* Do nothing */
}else
#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+ if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
int iCur = pTabItem->iCursor;
sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
@@ -5498,12 +5851,12 @@ WhereInfo *sqlite3WhereBegin(
/* noop */
}else
#endif
- if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
+ if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
&& (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
- testcase( pTab->nCol==BMS-1 );
- testcase( pTab->nCol==BMS );
+ testcase( !pWInfo->okOnePass && pTab->nCol==BMS-1 );
+ testcase( !pWInfo->okOnePass && pTab->nCol==BMS );
if( !pWInfo->okOnePass && pTab->nCol<BMS ){
Bitmask b = pTabItem->colUsed;
int n = 0;
@@ -5516,14 +5869,15 @@ WhereInfo *sqlite3WhereBegin(
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
}
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
- if( (pLevel->plan.wsFlags & WHERE_TEMP_INDEX)!=0 ){
- constructAutomaticIndex(pParse, sWBI.pWC, pTabItem, notReady, pLevel);
+ if( (pLoop->wsFlags & WHERE_TEMP_INDEX)!=0 ){
+ constructAutomaticIndex(pParse, &pWInfo->sWC, pTabItem, notReady, pLevel);
}else
#endif
- if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
- Index *pIx = pLevel->plan.u.pIdx;
+ if( pLoop->wsFlags & WHERE_INDEXED ){
+ Index *pIx = pLoop->u.btree.pIndex;
KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
- int iIndexCur = pLevel->iIdxCur;
+ /* FIXME: As an optimization use pTabItem->iCursor if WHERE_IDX_ONLY */
+ int iIndexCur = pLevel->iIdxCur = iIdxCur ? iIdxCur : pParse->nTab++;
assert( pIx->pSchema==pTab->pSchema );
assert( iIndexCur>=0 );
sqlite3VdbeAddOp4(v, OP_OpenRead, iIndexCur, pIx->tnum, iDb,
@@ -5531,7 +5885,7 @@ WhereInfo *sqlite3WhereBegin(
VdbeComment((v, "%s", pIx->zName));
}
sqlite3CodeVerifySchema(pParse, iDb);
- notReady &= ~getMask(sWBI.pWC->pMaskSet, pTabItem->iCursor);
+ notReady &= ~getMask(&pWInfo->sMaskSet, pTabItem->iCursor);
}
pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
if( db->mallocFailed ) goto whereBeginError;
@@ -5544,66 +5898,11 @@ WhereInfo *sqlite3WhereBegin(
for(ii=0; ii<nTabList; ii++){
pLevel = &pWInfo->a[ii];
explainOneScan(pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags);
- notReady = codeOneLoopStart(pWInfo, ii, wctrlFlags, notReady);
+ notReady = codeOneLoopStart(pWInfo, ii, notReady);
pWInfo->iContinue = pLevel->addrCont;
}
-#ifdef SQLITE_TEST /* For testing and debugging use only */
- /* Record in the query plan information about the current table
- ** and the index used to access it (if any). If the table itself
- ** is not used, its name is just '{}'. If no index is used
- ** the index is listed as "{}". If the primary key is used the
- ** index name is '*'.
- */
- for(ii=0; ii<nTabList; ii++){
- char *z;
- int n;
- int w;
- struct SrcList_item *pTabItem;
-
- pLevel = &pWInfo->a[ii];
- w = pLevel->plan.wsFlags;
- pTabItem = &pTabList->a[pLevel->iFrom];
- z = pTabItem->zAlias;
- if( z==0 ) z = pTabItem->pTab->zName;
- n = sqlite3Strlen30(z);
- if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){
- if( (w & WHERE_IDX_ONLY)!=0 && (w & WHERE_COVER_SCAN)==0 ){
- memcpy(&sqlite3_query_plan[nQPlan], "{}", 2);
- nQPlan += 2;
- }else{
- memcpy(&sqlite3_query_plan[nQPlan], z, n);
- nQPlan += n;
- }
- sqlite3_query_plan[nQPlan++] = ' ';
- }
- testcase( w & WHERE_ROWID_EQ );
- testcase( w & WHERE_ROWID_RANGE );
- if( w & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
- memcpy(&sqlite3_query_plan[nQPlan], "* ", 2);
- nQPlan += 2;
- }else if( (w & WHERE_INDEXED)!=0 && (w & WHERE_COVER_SCAN)==0 ){
- n = sqlite3Strlen30(pLevel->plan.u.pIdx->zName);
- if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){
- memcpy(&sqlite3_query_plan[nQPlan], pLevel->plan.u.pIdx->zName, n);
- nQPlan += n;
- sqlite3_query_plan[nQPlan++] = ' ';
- }
- }else{
- memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
- nQPlan += 3;
- }
- }
- while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){
- sqlite3_query_plan[--nQPlan] = 0;
- }
- sqlite3_query_plan[nQPlan] = 0;
- nQPlan = 0;
-#endif /* SQLITE_TEST // Testing and debugging use only */
-
- /* Record the continuation address in the WhereInfo structure. Then
- ** clean up and return.
- */
+ /* Done. */
return pWInfo;
/* Jump here if malloc fails */
@@ -5624,6 +5923,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
Vdbe *v = pParse->pVdbe;
int i;
WhereLevel *pLevel;
+ WhereLoop *pLoop;
SrcList *pTabList = pWInfo->pTabList;
sqlite3 *db = pParse->db;
@@ -5632,12 +5932,13 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
sqlite3ExprCacheClear(pParse);
for(i=pWInfo->nLevel-1; i>=0; i--){
pLevel = &pWInfo->a[i];
+ pLoop = pLevel->pWLoop;
sqlite3VdbeResolveLabel(v, pLevel->addrCont);
if( pLevel->op!=OP_Noop ){
sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
sqlite3VdbeChangeP5(v, pLevel->p5);
}
- if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
+ if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
struct InLoop *pIn;
int j;
sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
@@ -5652,12 +5953,12 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
if( pLevel->iLeftJoin ){
int addr;
addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin);
- assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
- || (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 );
- if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
+ assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+ || (pLoop->wsFlags & WHERE_INDEXED)!=0 );
+ if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){
sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
}
- if( pLevel->iIdxCur>=0 ){
+ if( pLoop->wsFlags & WHERE_INDEXED ){
sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
}
if( pLevel->op==OP_Return ){
@@ -5676,31 +5977,30 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
/* Close all of the cursors that were opened by sqlite3WhereBegin.
*/
- assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc );
+ assert( pWInfo->nLevel<=pTabList->nSrc );
for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
Index *pIdx = 0;
struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
Table *pTab = pTabItem->pTab;
assert( pTab!=0 );
+ pLoop = pLevel->pWLoop;
if( (pTab->tabFlags & TF_Ephemeral)==0
&& pTab->pSelect==0
&& (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
){
- int ws = pLevel->plan.wsFlags;
+ int ws = pLoop->wsFlags;
if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
}
- if( (ws & WHERE_INDEXED)!=0 && (ws & WHERE_TEMP_INDEX)==0 ){
+ if( (ws & WHERE_INDEXED)!=0 && (ws & (WHERE_IPK|WHERE_TEMP_INDEX))==0 ){
sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
}
}
- /* If this scan uses an index, make code substitutions to read data
- ** from the index in preference to the table. Sometimes, this means
- ** the table need never be read from. This is a performance boost,
- ** as the vdbe level waits until the table is read before actually
- ** seeking the table cursor to the record corresponding to the current
- ** position in the index.
+ /* If this scan uses an index, make VDBE code substitutions to read data
+ ** from the index instead of from the table where possible. In some cases
+ ** this optimization prevents the table from ever being read, which can
+ ** yield a significant performance boost.
**
** Calls to the code generator in between sqlite3WhereBegin and
** sqlite3WhereEnd will have created code that references the table
@@ -5708,12 +6008,12 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
** that reference the table and converts them into opcodes that
** reference the index.
*/
- if( pLevel->plan.wsFlags & WHERE_INDEXED ){
- pIdx = pLevel->plan.u.pIdx;
- }else if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){
+ if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){
+ pIdx = pLoop->u.btree.pIndex;
+ }else if( pLoop->wsFlags & WHERE_MULTI_OR ){
pIdx = pLevel->u.pCovidx;
}
- if( pIdx && !db->mallocFailed){
+ if( pIdx && !db->mallocFailed ){
int k, j, last;
VdbeOp *pOp;
@@ -5729,8 +6029,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
break;
}
}
- assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
- || j<pIdx->nColumn );
+ assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || j<pIdx->nColumn );
}else if( pOp->opcode==OP_Rowid ){
pOp->p1 = pLevel->iIdxCur;
pOp->opcode = OP_IdxRowid;
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-18 13:55:14 +0000