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-rw-r--r--src/analyze.c148
1 files changed, 97 insertions, 51 deletions
diff --git a/src/analyze.c b/src/analyze.c
index 76f8f818a..a7a8b6d66 100644
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -186,7 +186,7 @@ static void openStatTable(
sqlite3 *db = pParse->db;
Db *pDb;
Vdbe *v = sqlite3GetVdbe(pParse);
- int aRoot[ArraySize(aTable)];
+ u32 aRoot[ArraySize(aTable)];
u8 aCreateTbl[ArraySize(aTable)];
#ifdef SQLITE_ENABLE_STAT4
const int nToOpen = OptimizationEnabled(db,SQLITE_Stat4) ? 2 : 1;
@@ -215,7 +215,7 @@ static void openStatTable(
sqlite3NestedParse(pParse,
"CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
);
- aRoot[i] = pParse->regRoot;
+ aRoot[i] = (u32)pParse->regRoot;
aCreateTbl[i] = OPFLAG_P2ISREG;
}
}else{
@@ -235,7 +235,7 @@ static void openStatTable(
#endif
}else{
/* The sqlite_stat[134] table already exists. Delete all rows. */
- sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
+ sqlite3VdbeAddOp2(v, OP_Clear, (int)aRoot[i], iDb);
}
}
}
@@ -243,7 +243,7 @@ static void openStatTable(
/* Open the sqlite_stat[134] tables for writing. */
for(i=0; i<nToOpen; i++){
assert( i<ArraySize(aTable) );
- sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3);
+ sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, (int)aRoot[i], iDb, 3);
sqlite3VdbeChangeP5(v, aCreateTbl[i]);
VdbeComment((v, aTable[i].zName));
}
@@ -433,7 +433,6 @@ static void statInit(
+ sizeof(tRowcnt)*3*nColUp*(nCol+mxSample);
}
#endif
- db = sqlite3_context_db_handle(context);
p = sqlite3DbMallocZero(db, n);
if( p==0 ){
sqlite3_result_error_nomem(context);
@@ -848,32 +847,29 @@ static void statGet(
** * "WHERE a=? AND b=?" matches 2 rows.
**
** If D is the count of distinct values and K is the total number of
- ** rows, then each estimate is computed as:
+ ** rows, then each estimate is usually computed as:
**
** I = (K+D-1)/D
+ **
+ ** In other words, I is K/D rounded up to the next whole integer.
+ ** However, if I is between 1.0 and 1.1 (in other words if I is
+ ** close to 1.0 but just a little larger) then do not round up but
+ ** instead keep the I value at 1.0.
*/
- char *z;
- int i;
-
- char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 );
- if( zRet==0 ){
- sqlite3_result_error_nomem(context);
- return;
- }
+ sqlite3_str sStat; /* Text of the constructed "stat" line */
+ int i; /* Loop counter */
- sqlite3_snprintf(24, zRet, "%llu",
+ sqlite3StrAccumInit(&sStat, 0, 0, 0, (p->nKeyCol+1)*100);
+ sqlite3_str_appendf(&sStat, "%llu",
p->nSkipAhead ? (u64)p->nEst : (u64)p->nRow);
- z = zRet + sqlite3Strlen30(zRet);
for(i=0; i<p->nKeyCol; i++){
u64 nDistinct = p->current.anDLt[i] + 1;
u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
- sqlite3_snprintf(24, z, " %llu", iVal);
- z += sqlite3Strlen30(z);
+ if( iVal==2 && p->nRow*10 <= nDistinct*11 ) iVal = 1;
+ sqlite3_str_appendf(&sStat, " %llu", iVal);
assert( p->current.anEq[i] );
}
- assert( z[0]=='\0' && z>zRet );
-
- sqlite3_result_text(context, zRet, -1, sqlite3_free);
+ sqlite3ResultStrAccum(context, &sStat);
}
#ifdef SQLITE_ENABLE_STAT4
else if( eCall==STAT_GET_ROWID ){
@@ -892,6 +888,8 @@ static void statGet(
}
}else{
tRowcnt *aCnt = 0;
+ sqlite3_str sStat;
+ int i;
assert( p->iGet<p->nSample );
switch( eCall ){
@@ -903,23 +901,12 @@ static void statGet(
break;
}
}
-
- {
- char *zRet = sqlite3MallocZero(p->nCol * 25);
- if( zRet==0 ){
- sqlite3_result_error_nomem(context);
- }else{
- int i;
- char *z = zRet;
- for(i=0; i<p->nCol; i++){
- sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]);
- z += sqlite3Strlen30(z);
- }
- assert( z[0]=='\0' && z>zRet );
- z[-1] = '\0';
- sqlite3_result_text(context, zRet, -1, sqlite3_free);
- }
+ sqlite3StrAccumInit(&sStat, 0, 0, 0, p->nCol*100);
+ for(i=0; i<p->nCol; i++){
+ sqlite3_str_appendf(&sStat, "%llu ", (u64)aCnt[i]);
}
+ if( sStat.nChar ) sStat.nChar--;
+ sqlite3ResultStrAccum(context, &sStat);
}
#endif /* SQLITE_ENABLE_STAT4 */
#ifndef SQLITE_DEBUG
@@ -966,9 +953,10 @@ static void analyzeVdbeCommentIndexWithColumnName(
if( NEVER(i==XN_ROWID) ){
VdbeComment((v,"%s.rowid",pIdx->zName));
}else if( i==XN_EXPR ){
+ assert( pIdx->bHasExpr );
VdbeComment((v,"%s.expr(%d)",pIdx->zName, k));
}else{
- VdbeComment((v,"%s.%s", pIdx->zName, pIdx->pTable->aCol[i].zName));
+ VdbeComment((v,"%s.%s", pIdx->zName, pIdx->pTable->aCol[i].zCnName));
}
}
#else
@@ -1006,16 +994,20 @@ static void analyzeOneTable(
int regIdxname = iMem++; /* Register containing index name */
int regStat1 = iMem++; /* Value for the stat column of sqlite_stat1 */
int regPrev = iMem; /* MUST BE LAST (see below) */
+#ifdef SQLITE_ENABLE_STAT4
+ int doOnce = 1; /* Flag for a one-time computation */
+#endif
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
- Table *pStat1 = 0;
+ Table *pStat1 = 0;
#endif
- pParse->nMem = MAX(pParse->nMem, iMem);
+ sqlite3TouchRegister(pParse, iMem);
+ assert( sqlite3NoTempsInRange(pParse, regNewRowid, iMem) );
v = sqlite3GetVdbe(pParse);
if( v==0 || NEVER(pTab==0) ){
return;
}
- if( pTab->tnum==0 ){
+ if( !IsOrdinaryTable(pTab) ){
/* Do not gather statistics on views or virtual tables */
return;
}
@@ -1042,7 +1034,7 @@ static void analyzeOneTable(
memcpy(pStat1->zName, "sqlite_stat1", 13);
pStat1->nCol = 3;
pStat1->iPKey = -1;
- sqlite3VdbeAddOp4(pParse->pVdbe, OP_Noop, 0, 0, 0,(char*)pStat1,P4_DYNBLOB);
+ sqlite3VdbeAddOp4(pParse->pVdbe, OP_Noop, 0, 0, 0,(char*)pStat1,P4_DYNAMIC);
}
#endif
@@ -1116,7 +1108,7 @@ static void analyzeOneTable(
** the regPrev array and a trailing rowid (the rowid slot is required
** when building a record to insert into the sample column of
** the sqlite_stat4 table. */
- pParse->nMem = MAX(pParse->nMem, regPrev+nColTest);
+ sqlite3TouchRegister(pParse, regPrev+nColTest);
/* Open a read-only cursor on the index being analyzed. */
assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
@@ -1288,7 +1280,35 @@ static void analyzeOneTable(
int addrIsNull;
u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
- pParse->nMem = MAX(pParse->nMem, regCol+nCol);
+ if( doOnce ){
+ int mxCol = nCol;
+ Index *pX;
+
+ /* Compute the maximum number of columns in any index */
+ for(pX=pTab->pIndex; pX; pX=pX->pNext){
+ int nColX; /* Number of columns in pX */
+ if( !HasRowid(pTab) && IsPrimaryKeyIndex(pX) ){
+ nColX = pX->nKeyCol;
+ }else{
+ nColX = pX->nColumn;
+ }
+ if( nColX>mxCol ) mxCol = nColX;
+ }
+
+ /* Allocate space to compute results for the largest index */
+ sqlite3TouchRegister(pParse, regCol+mxCol);
+ doOnce = 0;
+#ifdef SQLITE_DEBUG
+ /* Verify that the call to sqlite3ClearTempRegCache() below
+ ** really is needed.
+ ** https://sqlite.org/forum/forumpost/83cb4a95a0 (2023-03-25)
+ */
+ testcase( !sqlite3NoTempsInRange(pParse, regEq, regCol+mxCol) );
+#endif
+ sqlite3ClearTempRegCache(pParse); /* tag-20230325-1 */
+ assert( sqlite3NoTempsInRange(pParse, regEq, regCol+mxCol) );
+ }
+ assert( sqlite3NoTempsInRange(pParse, regEq, regCol+nCol) );
addrNext = sqlite3VdbeCurrentAddr(v);
callStatGet(pParse, regStat, STAT_GET_ROWID, regSampleRowid);
@@ -1369,6 +1389,11 @@ static void analyzeDatabase(Parse *pParse, int iDb){
for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
Table *pTab = (Table*)sqliteHashData(k);
analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);
+#ifdef SQLITE_ENABLE_STAT4
+ iMem = sqlite3FirstAvailableRegister(pParse, iMem);
+#else
+ assert( iMem==sqlite3FirstAvailableRegister(pParse,iMem) );
+#endif
}
loadAnalysis(pParse, iDb);
}
@@ -1609,6 +1634,8 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
** and its contents.
*/
void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
+ assert( db!=0 );
+ assert( pIdx!=0 );
#ifdef SQLITE_ENABLE_STAT4
if( pIdx->aSample ){
int j;
@@ -1618,7 +1645,7 @@ void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
}
sqlite3DbFree(db, pIdx->aSample);
}
- if( db && db->pnBytesFreed==0 ){
+ if( db->pnBytesFreed==0 ){
pIdx->nSample = 0;
pIdx->aSample = 0;
}
@@ -1754,6 +1781,10 @@ static int loadStatTbl(
pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
assert( pIdx==0 || pIdx->nSample==0 );
if( pIdx==0 ) continue;
+ if( pIdx->aSample!=0 ){
+ /* The same index appears in sqlite_stat4 under multiple names */
+ continue;
+ }
assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 );
if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){
nIdxCol = pIdx->nKeyCol;
@@ -1761,6 +1792,7 @@ static int loadStatTbl(
nIdxCol = pIdx->nColumn;
}
pIdx->nSampleCol = nIdxCol;
+ pIdx->mxSample = nSample;
nByte = sizeof(IndexSample) * nSample;
nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample;
nByte += nIdxCol * sizeof(tRowcnt); /* Space for Index.aAvgEq[] */
@@ -1772,6 +1804,7 @@ static int loadStatTbl(
}
pSpace = (tRowcnt*)&pIdx->aSample[nSample];
pIdx->aAvgEq = pSpace; pSpace += nIdxCol;
+ pIdx->pTable->tabFlags |= TF_HasStat4;
for(i=0; i<nSample; i++){
pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol;
pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol;
@@ -1799,6 +1832,11 @@ static int loadStatTbl(
if( zIndex==0 ) continue;
pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
if( pIdx==0 ) continue;
+ if( pIdx->nSample>=pIdx->mxSample ){
+ /* Too many slots used because the same index appears in
+ ** sqlite_stat4 using multiple names */
+ continue;
+ }
/* This next condition is true if data has already been loaded from
** the sqlite_stat4 table. */
nCol = pIdx->nSampleCol;
@@ -1811,14 +1849,15 @@ static int loadStatTbl(
decodeIntArray((char*)sqlite3_column_text(pStmt,2),nCol,pSample->anLt,0,0);
decodeIntArray((char*)sqlite3_column_text(pStmt,3),nCol,pSample->anDLt,0,0);
- /* Take a copy of the sample. Add two 0x00 bytes the end of the buffer.
+ /* Take a copy of the sample. Add 8 extra 0x00 bytes the end of the buffer.
** This is in case the sample record is corrupted. In that case, the
** sqlite3VdbeRecordCompare() may read up to two varints past the
** end of the allocated buffer before it realizes it is dealing with
- ** a corrupt record. Adding the two 0x00 bytes prevents this from causing
+ ** a corrupt record. Or it might try to read a large integer from the
+ ** buffer. In any case, eight 0x00 bytes prevents this from causing
** a buffer overread. */
pSample->n = sqlite3_column_bytes(pStmt, 4);
- pSample->p = sqlite3DbMallocZero(db, pSample->n + 2);
+ pSample->p = sqlite3DbMallocZero(db, pSample->n + 8);
if( pSample->p==0 ){
sqlite3_finalize(pStmt);
return SQLITE_NOMEM_BKPT;
@@ -1839,11 +1878,15 @@ static int loadStatTbl(
*/
static int loadStat4(sqlite3 *db, const char *zDb){
int rc = SQLITE_OK; /* Result codes from subroutines */
+ const Table *pStat4;
assert( db->lookaside.bDisable );
- if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
+ if( OptimizationEnabled(db, SQLITE_Stat4)
+ && (pStat4 = sqlite3FindTable(db, "sqlite_stat4", zDb))!=0
+ && IsOrdinaryTable(pStat4)
+ ){
rc = loadStatTbl(db,
- "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx",
+ "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx COLLATE nocase",
"SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
zDb
);
@@ -1878,6 +1921,7 @@ int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
char *zSql;
int rc = SQLITE_OK;
Schema *pSchema = db->aDb[iDb].pSchema;
+ const Table *pStat1;
assert( iDb>=0 && iDb<db->nDb );
assert( db->aDb[iDb].pBt!=0 );
@@ -1900,7 +1944,9 @@ int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
/* Load new statistics out of the sqlite_stat1 table */
sInfo.db = db;
sInfo.zDatabase = db->aDb[iDb].zDbSName;
- if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)!=0 ){
+ if( (pStat1 = sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase))
+ && IsOrdinaryTable(pStat1)
+ ){
zSql = sqlite3MPrintf(db,
"SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
if( zSql==0 ){
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-18 03:59:32 +0000