Adjust overly strict Assert

david-rowley · david-rowley · commit e1a0f6a98306 · 2019-07-22T10:29:41.000+12:00
3373c71 changed how we determine EquivalenceClasses for relations and added an Assert to ensure all relations mentioned in each EC's ec_relids was a RELOPT_BASEREL. However, the join removal code may remove a LEFT JOIN and since it does not clean up EC members belonging to the removed relations it can leave RELOPT_DEADREL rels in ec_relids. Fix this by adjusting the Assert to allow RELOPT_DEADREL rels too. Reported-by: sqlsmith via Andreas Seltenreich Discussion: https://postgr.es/m/87y30r8sls.fsf@ansel.ydns.eu
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c
@@ -761,7 +761,8 @@ get_eclass_for_sort_expr(PlannerInfo *root,
 		{
 			RelOptInfo *rel = root->simple_rel_array[i];
 
-			Assert(rel->reloptkind == RELOPT_BASEREL);
+			Assert(rel->reloptkind == RELOPT_BASEREL ||
+				   rel->reloptkind == RELOPT_DEADREL);
 
 			rel->eclass_indexes = bms_add_member(rel->eclass_indexes,
 												 ec_index);

Original file line number	Diff line number	Diff line change
`@@ -761,7 +761,8 @@ get_eclass_for_sort_expr(PlannerInfo *root,`
`761`	`761`	`{`
`762`	`762`	`RelOptInfo *rel = root->simple_rel_array[i];`
`763`	`763`
`764`		`- Assert(rel->reloptkind == RELOPT_BASEREL);`
	`764`	`+ Assert(rel->reloptkind == RELOPT_BASEREL \|\|`
	`765`	`+ rel->reloptkind == RELOPT_DEADREL);`
`765`	`766`
`766`	`767`	`rel->eclass_indexes = bms_add_member(rel->eclass_indexes,`
`767`	`768`	`ec_index);`