Provide hints to the btree layer during the creation of transient tables
when it is possible for those tables to use a hash rather than a binary tree.
No use is current made of those hints, though assert() statement verify
their accuracy.
FossilOrigin-Name: 4fead8e714c7e50a9d246467e62bc846ef6180a0
diff --git a/src/expr.c b/src/expr.c
index 33864b2..a23a7b1 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1535,8 +1535,8 @@
#endif
/*
-** Generate code for scalar subqueries used as an expression
-** and IN operators. Examples:
+** Generate code for scalar subqueries used as a subquery expression, EXISTS,
+** or IN operators. Examples:
**
** (SELECT a FROM b) -- subquery
** EXISTS (SELECT a FROM b) -- EXISTS subquery
@@ -1599,10 +1599,10 @@
switch( pExpr->op ){
case TK_IN: {
- char affinity;
- KeyInfo keyInfo;
- int addr; /* Address of OP_OpenEphemeral instruction */
- Expr *pLeft = pExpr->pLeft;
+ char affinity; /* Affinity of the LHS of the IN */
+ KeyInfo keyInfo; /* Keyinfo for the generated table */
+ int addr; /* Address of OP_OpenEphemeral instruction */
+ Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
if( rMayHaveNull ){
sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
@@ -1625,6 +1625,7 @@
*/
pExpr->iTable = pParse->nTab++;
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
+ if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
memset(&keyInfo, 0, sizeof(keyInfo));
keyInfo.nField = 1;