Hi, On 2020-02-09 21:25:47 -0600, Justin Pryzby wrote: > I believe the 2nd hunk should reset node->hashnulls, rather than reset > ->hashtable a 2nd time: > > @@ -505,7 +505,10 @@ buildSubPlanHash(SubPlanState *node, ExprContext > *econtext) > if (nbuckets < 1) > nbuckets = 1; > > - node->hashtable = BuildTupleHashTable(node->parent, > + if (node->hashtable) > + ResetTupleHashTable(node->hashtable); > + else > + node->hashtable = BuildTupleHashTableExt(node->parent, > > node->descRight, > > ncols, > > node->keyColIdx, > ... > > @@ -527,7 +531,11 @@ buildSubPlanHash(SubPlanState *node, ExprContext > *econtext) > if (nbuckets < 1) > nbuckets = 1; > } > - node->hashnulls = BuildTupleHashTable(node->parent, > + > + if (node->hashnulls) > + ResetTupleHashTable(node->hashtable); > + else > + node->hashnulls = BuildTupleHashTableExt(node->parent, > > node->descRight, > > ncols, > > node->keyColIdx,
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? - Andres
