Merge all the latest trunk enhancements into jsonb branch.

FossilOrigin-Name: ac242c4d47ec36aab1c2fa5e65e7b595e686f49473b75bd63708d05c59ce3f0f

5 files changed, 156 insertions, 20 deletions

diff --git a/src/build.c b/src/build.c
index 59e3e23f0..3e011c625 100644
--- a/src/build.c
+++ b/src/build.c
@@ -2302,7 +2302,7 @@ static int isDupColumn(Index *pIdx, int nKey, Index *pPk, int iCol){
 ** The colNotIdxed mask is AND-ed with the SrcList.a[].colUsed mask
 ** to determine if the index is covering index.
 */
-static void recomputeColumnsNotIndexed(Index *pIdx){
+static void recomputeColumnsNotIndexed(Parse *pParse, Index *pIdx){
   Bitmask m = 0;
   int j;
   Table *pTab = pIdx->pTable;
@@ -2493,7 +2493,7 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
   }
   assert( pPk->nColumn==j );
   assert( pTab->nNVCol<=j );
-  recomputeColumnsNotIndexed(pPk);
+  recomputeColumnsNotIndexed(pParse, pPk);
 }
 
 
@@ -4273,7 +4273,7 @@ void sqlite3CreateIndex(
   ** it as a covering index */
   assert( HasRowid(pTab)
       || pTab->iPKey<0 || sqlite3TableColumnToIndex(pIndex, pTab->iPKey)>=0 );
-  recomputeColumnsNotIndexed(pIndex);
+  recomputeColumnsNotIndexed(pParse, pIndex);
   if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){
     pIndex->isCovering = 1;
     for(j=0; j<pTab->nCol; j++){
diff --git a/src/expr.c b/src/expr.c
index 63c5a8faa..f7290262e 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -4253,6 +4253,41 @@ static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
 
 
 /*
+** Expresion pExpr is guaranteed to be a TK_COLUMN or equivalent. This
+** function checks the Parse.pIdxPartExpr list to see if this column
+** can be replaced with a constant value. If so, it generates code to
+** put the constant value in a register (ideally, but not necessarily, 
+** register iTarget) and returns the register number.
+**
+** Or, if the TK_COLUMN cannot be replaced by a constant, zero is 
+** returned.
+*/
+static int exprPartidxExprLookup(Parse *pParse, Expr *pExpr, int iTarget){
+  IndexedExpr *p;
+  for(p=pParse->pIdxPartExpr; p; p=p->pIENext){
+    if( pExpr->iColumn==p->iIdxCol && pExpr->iTable==p->iDataCur ){
+      Vdbe *v = pParse->pVdbe;
+      int addr = 0;
+      int ret;
+
+      if( p->bMaybeNullRow ){
+        addr = sqlite3VdbeAddOp1(v, OP_IfNullRow, p->iIdxCur);
+      }
+      ret = sqlite3ExprCodeTarget(pParse, p->pExpr, iTarget);
+      sqlite3VdbeAddOp4(pParse->pVdbe, OP_Affinity, ret, 1, 0,
+                        (const char*)&p->aff, 1);
+      if( addr ){
+        sqlite3VdbeJumpHere(v, addr);
+        sqlite3VdbeChangeP3(v, addr, ret);
+      }
+      return ret;
+    }
+  }
+  return 0;
+}
+
+
+/*
 ** Generate code into the current Vdbe to evaluate the given
 ** expression.  Attempt to store the results in register "target".
 ** Return the register where results are stored.
@@ -4409,6 +4444,11 @@ expr_code_doover:
           iTab = pParse->iSelfTab - 1;
         }
       }
+      else if( pParse->pIdxPartExpr 
+       && 0!=(r1 = exprPartidxExprLookup(pParse, pExpr, target))
+      ){
+        return r1;
+      }
       assert( ExprUseYTab(pExpr) );
       assert( pExpr->y.pTab!=0 );
       iReg = sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,
diff --git a/src/prepare.c b/src/prepare.c
index 9f843faa8..d3e134e76 100644
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -598,8 +598,6 @@ void sqlite3ParseObjectReset(Parse *pParse){
   db->lookaside.sz = db->lookaside.bDisable ? 0 : db->lookaside.szTrue;
   assert( pParse->db->pParse==pParse );
   db->pParse = pParse->pOuterParse;
-  pParse->db = 0;
-  pParse->disableLookaside = 0;
 }
 
 /*
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 225e54800..722197499 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3790,6 +3790,7 @@ struct Parse {
   int *aLabel;         /* Space to hold the labels */
   ExprList *pConstExpr;/* Constant expressions */
   IndexedExpr *pIdxEpr;/* List of expressions used by active indexes */
+  IndexedExpr *pIdxPartExpr; /* Exprs constrained by index WHERE clauses */
   Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */
   yDbMask cookieMask;  /* Bitmask of schema verified databases */
diff --git a/src/where.c b/src/where.c
index 3a865d3f1..0b516a672 100644
--- a/src/where.c
+++ b/src/where.c
@@ -1142,13 +1142,17 @@ static SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
   WhereLoop *pLoop = pLevel->pWLoop;   /* The loop being coded */
   int iCur;                            /* Cursor for table getting the filter */
   IndexedExpr *saved_pIdxEpr;          /* saved copy of Parse.pIdxEpr */
+  IndexedExpr *saved_pIdxPartExpr;     /* saved copy of Parse.pIdxPartExpr */
 
   saved_pIdxEpr = pParse->pIdxEpr;
+  saved_pIdxPartExpr = pParse->pIdxPartExpr;
   pParse->pIdxEpr = 0;
+  pParse->pIdxPartExpr = 0;
 
   assert( pLoop!=0 );
   assert( v!=0 );
   assert( pLoop->wsFlags & WHERE_BLOOMFILTER );
+  assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 );
 
   addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
   do{
@@ -1238,6 +1242,7 @@ static SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
   }while( iLevel < pWInfo->nLevel );
   sqlite3VdbeJumpHere(v, addrOnce);
   pParse->pIdxEpr = saved_pIdxEpr;
+  pParse->pIdxPartExpr = saved_pIdxPartExpr;
 }
 
 
@@ -3498,6 +3503,101 @@ static SQLITE_NOINLINE u32 whereIsCoveringIndex(
 }
 
 /*
+** This is an sqlite3ParserAddCleanup() callback that is invoked to
+** free the Parse->pIdxEpr list when the Parse object is destroyed.
+*/
+static void whereIndexedExprCleanup(sqlite3 *db, void *pObject){
+  IndexedExpr **pp = (IndexedExpr**)pObject;
+  while( *pp!=0 ){
+    IndexedExpr *p = *pp;
+    *pp = p->pIENext;
+    sqlite3ExprDelete(db, p->pExpr);
+    sqlite3DbFreeNN(db, p);
+  }
+}
+
+/*
+** This function is called for a partial index - one with a WHERE clause - in 
+** two scenarios. In both cases, it determines whether or not the WHERE 
+** clause on the index implies that a column of the table may be safely
+** replaced by a constant expression. For example, in the following 
+** SELECT:
+**
+**   CREATE INDEX i1 ON t1(b, c) WHERE a=<expr>;
+**   SELECT a, b, c FROM t1 WHERE a=<expr> AND b=?;
+**
+** The "a" in the select-list may be replaced by <expr>, iff:
+**
+**    (a) <expr> is a constant expression, and
+**    (b) The (a=<expr>) comparison uses the BINARY collation sequence, and
+**    (c) Column "a" has an affinity other than NONE or BLOB.
+**
+** If argument pItem is NULL, then pMask must not be NULL. In this case this 
+** function is being called as part of determining whether or not pIdx
+** is a covering index. This function clears any bits in (*pMask) 
+** corresponding to columns that may be replaced by constants as described
+** above.
+**
+** Otherwise, if pItem is not NULL, then this function is being called
+** as part of coding a loop that uses index pIdx. In this case, add entries
+** to the Parse.pIdxPartExpr list for each column that can be replaced
+** by a constant.
+*/
+static void wherePartIdxExpr(
+  Parse *pParse,                  /* Parse context */
+  Index *pIdx,                    /* Partial index being processed */
+  Expr *pPart,                    /* WHERE clause being processed */
+  Bitmask *pMask,                 /* Mask to clear bits in */
+  int iIdxCur,                    /* Cursor number for index */
+  SrcItem *pItem                  /* The FROM clause entry for the table */
+){
+  assert( pItem==0 || (pItem->fg.jointype & JT_RIGHT)==0 );
+  assert( (pItem==0 || pMask==0) && (pMask!=0 || pItem!=0) );
+
+  if( pPart->op==TK_AND ){
+    wherePartIdxExpr(pParse, pIdx, pPart->pRight, pMask, iIdxCur, pItem);
+    pPart = pPart->pLeft;
+  }
+
+  if( (pPart->op==TK_EQ || pPart->op==TK_IS) ){
+    Expr *pLeft = pPart->pLeft;
+    Expr *pRight = pPart->pRight;
+    u8 aff;
+
+    assert( pRight->op!=TK_COLUMN );
+    if( pLeft->op!=TK_COLUMN ) return;
+    if( !sqlite3ExprIsConstant(pRight) ) return;
+    if( !sqlite3IsBinary(sqlite3ExprCompareCollSeq(pParse, pPart)) ) return;
+    if( NEVER(pLeft->iColumn<0) ) return;
+    aff = pIdx->pTable->aCol[pLeft->iColumn].affinity;
+    if( aff>=SQLITE_AFF_TEXT ){
+      if( pItem ){
+        sqlite3 *db = pParse->db;
+        IndexedExpr *p = (IndexedExpr*)sqlite3DbMallocRaw(db, sizeof(*p));
+        if( p ){
+          int bNullRow = (pItem->fg.jointype&(JT_LEFT|JT_LTORJ))!=0;
+          p->pExpr = sqlite3ExprDup(db, pRight, 0);
+          p->iDataCur = pItem->iCursor;
+          p->iIdxCur = iIdxCur;
+          p->iIdxCol = pLeft->iColumn;
+          p->bMaybeNullRow = bNullRow;
+          p->pIENext = pParse->pIdxPartExpr;
+          p->aff = aff;
+          pParse->pIdxPartExpr = p;
+          if( p->pIENext==0 ){
+            void *pArg = (void*)&pParse->pIdxPartExpr;
+            sqlite3ParserAddCleanup(pParse, whereIndexedExprCleanup, pArg);
+          }
+        }
+      }else if( pLeft->iColumn<(BMS-1) ){
+        *pMask &= ~((Bitmask)1 << pLeft->iColumn);
+      }
+    }
+  }
+}
+
+
+/*
 ** Add all WhereLoop objects for a single table of the join where the table
 ** is identified by pBuilder->pNew->iTab.  That table is guaranteed to be
 ** a b-tree table, not a virtual table.
@@ -3712,6 +3812,11 @@ static int whereLoopAddBtree(
         pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
       }else{
         m = pSrc->colUsed & pProbe->colNotIdxed;
+        if( pProbe->pPartIdxWhere ){
+          wherePartIdxExpr(
+              pWInfo->pParse, pProbe, pProbe->pPartIdxWhere, &m, 0, 0
+          );
+        }
         pNew->wsFlags = WHERE_INDEXED;
         if( m==TOPBIT || (pProbe->bHasExpr && !pProbe->bHasVCol && m!=0) ){
           u32 isCov = whereIsCoveringIndex(pWInfo, pProbe, pSrc->iCursor);
@@ -5668,20 +5773,6 @@ static SQLITE_NOINLINE void whereCheckIfBloomFilterIsUseful(
 }
 
 /*
-** This is an sqlite3ParserAddCleanup() callback that is invoked to
-** free the Parse->pIdxEpr list when the Parse object is destroyed.
-*/
-static void whereIndexedExprCleanup(sqlite3 *db, void *pObject){
-  Parse *pParse = (Parse*)pObject;
-  while( pParse->pIdxEpr!=0 ){
-    IndexedExpr *p = pParse->pIdxEpr;
-    pParse->pIdxEpr = p->pIENext;
-    sqlite3ExprDelete(db, p->pExpr);
-    sqlite3DbFreeNN(db, p);
-  }
-}
-
-/*
 ** The index pIdx is used by a query and contains one or more expressions.
 ** In other words pIdx is an index on an expression.  iIdxCur is the cursor
 ** number for the index and iDataCur is the cursor number for the corresponding
@@ -5742,7 +5833,8 @@ static SQLITE_NOINLINE void whereAddIndexedExpr(
 #endif
     pParse->pIdxEpr = p;
     if( p->pIENext==0 ){
-      sqlite3ParserAddCleanup(pParse, whereIndexedExprCleanup, pParse);
+      void *pArg = (void*)&pParse->pIdxEpr;
+      sqlite3ParserAddCleanup(pParse, whereIndexedExprCleanup, pArg);
     }
   }
 }
@@ -6354,6 +6446,11 @@ WhereInfo *sqlite3WhereBegin(
         if( pIx->bHasExpr && OptimizationEnabled(db, SQLITE_IndexedExpr) ){
           whereAddIndexedExpr(pParse, pIx, iIndexCur, pTabItem);
         }
+        if( pIx->pPartIdxWhere && (pTabItem->fg.jointype & JT_RIGHT)==0 ){
+          wherePartIdxExpr(
+              pParse, pIx, pIx->pPartIdxWhere, 0, iIndexCur, pTabItem
+          );
+        }
       }
       pLevel->iIdxCur = iIndexCur;
       assert( pIx!=0 );