On Sun, Feb 09, 2020 at 08:01:26PM -0800, Andres Freund wrote:
> Ugh, that indeed looks wrong. Did you check whether it can actively
> cause wrong query results? If so, did you do theoretically, or got to a
> query returning wrong results?
Actually .. I can "theoretically" prove that there's no wrong results from that
patch...since in that file it has no effect, the tested variables being zeroed
few lines earlier:
@@ -499,51 +499,60 @@ buildSubPlanHash(SubPlanState *node, ExprContext
*econtext)
* node->hashtable = NULL;
* node->hashnulls = NULL;
node->havehashrows = false;
node->havenullrows = false;
nbuckets = (long) Min(planstate->plan->plan_rows, (double) LONG_MAX);
if (nbuckets < 1)
nbuckets = 1;
- node->hashtable = BuildTupleHashTable(node->parent,
-
node->descRight,
-
ncols,
-
node->keyColIdx,
-
node->tab_eq_funcoids,
-
node->tab_hash_funcs,
-
nbuckets,
-
0,
-
node->hashtablecxt,
-
node->hashtempcxt,
-
false);
*+ if (node->hashtable)
+ ResetTupleHashTable(node->hashtable);
+ else
+ node->hashtable = BuildTupleHashTableExt(node->parent,
...
*+ if (node->hashnulls)
+ ResetTupleHashTable(node->hashtable);
+ else
+ node->hashnulls = BuildTupleHashTableExt(node->parent,
+
node->descRight,
