Keep the planner from failing on "WHERE false AND something IN (SELECT ...)".

eval_const_expressions simplifies this to just "WHERE false", but we have
already done pull_up_IN_clauses so the IN join will be done, or at least
planned, anyway.  The trouble case comes when the sub-SELECT is itself a join
and we decide to implement the IN by unique-ifying the sub-SELECT outputs:
with no remaining reference to the output Vars in WHERE, we won't have
propagated the Vars up to the upper join point, leading to "variable not found
in subplan target lists" error.  Fix by adding an extra scan of in_info_list
and forcing all Vars mentioned therein to be propagated up to the IN join
point.  Per bug report from Miroslav Sulc.

diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c
index e016cf1da85a4e6ad74a924af5c45519da860460..29c587a4e137e28be0c91e82bba1379beaa2e92f 100644 (file)
--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -138,6 +138,40 @@ build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
        }
 }
 
+/*
+ * add_IN_vars_to_tlists
+ *       Add targetlist entries for each var needed in InClauseInfo entries
+ *       to the appropriate base relations.
+ *
+ * Normally this is a waste of time because scanning of the WHERE clause
+ * will have added them.  But it is possible that eval_const_expressions()
+ * simplified away all references to the vars after the InClauseInfos were
+ * made.  We need the IN's righthand-side vars to be available at the join
+ * anyway, in case we try to unique-ify the subselect's outputs.  (The only
+ * known case that provokes this is "WHERE false AND foo IN (SELECT ...)".
+ * We don't try to be very smart about such cases, just correct.)
+ */
+void
+add_IN_vars_to_tlists(PlannerInfo *root)
+{
+       ListCell   *l;
+
+       foreach(l, root->in_info_list)
+       {
+               InClauseInfo *ininfo = (InClauseInfo *) lfirst(l);
+               List       *in_vars;
+
+               in_vars = pull_var_clause((Node *) ininfo->sub_targetlist, false);
+               if (in_vars != NIL)
+               {
+                       add_vars_to_targetlist(root, in_vars,
+                                                                  bms_union(ininfo->lefthand,
+                                                                                        ininfo->righthand));
+                       list_free(in_vars);
+               }
+       }
+}
+
 /*
  * add_vars_to_targetlist
  *       For each variable appearing in the list, add it to the owning

diff --git a/src/backend/optimizer/plan/planmain.c b/src/backend/optimizer/plan/planmain.c
index d3bcb3ef3c8ac4897013f2e657320c559705247f..5ccc599abf48ce710db9e922587a3f45d0c47bde 100644 (file)
--- a/src/backend/optimizer/plan/planmain.c
+++ b/src/backend/optimizer/plan/planmain.c
@@ -178,6 +178,13 @@ query_planner(PlannerInfo *root, List *tlist, double tuple_fraction,
 
        joinlist = deconstruct_jointree(root);
 
+       /*
+        * Vars mentioned in InClauseInfo items also have to be added to baserel
+        * targetlists.  Nearly always, they'd have got there from the original
+        * WHERE qual, but in corner cases maybe not.
+        */
+       add_IN_vars_to_tlists(root);
+
        /*
         * Use the completed lists of equijoined keys to deduce any implied but
         * unstated equalities (for example, A=B and B=C imply A=C).

diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index d5e21509925b3267448f51c97fb1002a18e413c9..1b19c2c4c89aa567bc6004bc8d6fe57f47c8ba9d 100644 (file)
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -69,6 +69,7 @@ extern int    join_collapse_limit;
 
 extern void add_base_rels_to_query(PlannerInfo *root, Node *jtnode);
 extern void build_base_rel_tlists(PlannerInfo *root, List *final_tlist);
+extern void add_IN_vars_to_tlists(PlannerInfo *root);
 extern List *deconstruct_jointree(PlannerInfo *root);
 extern void process_implied_equality(PlannerInfo *root,
                                                 Node *item1, Node *item2,