Proposed optimization to the IS NULL and NOT NULL operators that avoids

loading the entire content of larges strings and BLOBs.  Response to
[forum:/info/3c08d4715dc05b00|forum post 3c08d4715dc05b00].

FossilOrigin-Name: 45f171565442f9fd6574fb93ae7abe83c168b20be68af42531bc55571450d3ab

1 files changed, 2 insertions, 0 deletions

diff --git a/src/expr.c b/src/expr.c
index baa0fe647..bceb5efb0 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -5241,6 +5241,7 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
       assert( TK_ISNULL==OP_IsNull );   testcase( op==TK_ISNULL );
       assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      sqlite3VdbeTypeofColumn(v, r1);
       sqlite3VdbeAddOp2(v, op, r1, dest);
       VdbeCoverageIf(v, op==TK_ISNULL);
       VdbeCoverageIf(v, op==TK_NOTNULL);
@@ -5415,6 +5416,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
     case TK_ISNULL:
     case TK_NOTNULL: {
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      sqlite3VdbeTypeofColumn(v, r1);
       sqlite3VdbeAddOp2(v, op, r1, dest);
       testcase( op==TK_ISNULL );   VdbeCoverageIf(v, op==TK_ISNULL);
       testcase( op==TK_NOTNULL );  VdbeCoverageIf(v, op==TK_NOTNULL);