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 5a9b2464faec915dfb503aae2bfc3d0477d94f4c..b4ba40ed42b760bfd02affd888308236003d8ee6 100644 (file)
--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -126,6 +126,40 @@ 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 0bb84f1a4c88a191bcd03fd75db63f2af4ba6805..8bdf5e1a9673f04cc159271a83bc76ce6b31c9b4 100644 (file)
--- a/src/backend/optimizer/plan/planmain.c
+++ b/src/backend/optimizer/plan/planmain.c
@@ -156,6 +156,13 @@ query_planner(PlannerInfo *root, List *tlist, double tuple_fraction,
 
        (void) distribute_quals_to_rels(root, (Node *) parse->jointree, false);
 
+       /*
+        * 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 2b8bbc13e809723858c6c6cf9c3f8845854ccc1a..b310e6045e2464a5ac474807424563191ab73bb6 100644 (file)
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -67,6 +67,7 @@ extern bool is_projection_capable_plan(Plan *plan);
  */
 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 Relids distribute_quals_to_rels(PlannerInfo *root, Node *jtnode,
                                                 bool below_outer_join);
 extern void process_implied_equality(PlannerInfo *root,