Back-patch fix to make partial indexes usable on relations other than

the first one listed in a query.  Per request from Oleg.

diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 0b934919cb0060904298254699b7d122615b9f2e..3d7f5d691e7c79e4f65c6954d0fbb5daa9e1512f 100644 (file)
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -34,6 +34,7 @@
 #include "parser/parse_coerce.h"
 #include "parser/parse_expr.h"
 #include "parser/parse_oper.h"
+#include "rewrite/rewriteManip.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
@@ -78,7 +79,7 @@ static bool match_clause_to_indexkey(RelOptInfo *rel, IndexOptInfo *index,
                                                 int indexkey, Oid opclass,
                                                 Expr *clause, bool join);
 static bool pred_test(List *predicate_list, List *restrictinfo_list,
-                 List *joininfo_list);
+                 List *joininfo_list, int relvarno);
 static bool pred_test_restrict_list(Expr *predicate, List *restrictinfo_list);
 static bool pred_test_recurse_clause(Expr *predicate, Node *clause);
 static bool pred_test_recurse_pred(Expr *predicate, Node *clause);
@@ -152,7 +153,8 @@ create_index_paths(Query *root, RelOptInfo *rel)
                 * predicate test.
                 */
                if (index->indpred != NIL)
-                       if (!pred_test(index->indpred, restrictinfo_list, joininfo_list))
+                       if (!pred_test(index->indpred, restrictinfo_list, joininfo_list,
+                                                  lfirsti(rel->relids)))
                                continue;
 
                /*
@@ -955,7 +957,8 @@ indexable_operator(Expr *clause, Oid opclass, bool indexkey_on_left)
  *       to CNF format). --Nels, Jan '93
  */
 static bool
-pred_test(List *predicate_list, List *restrictinfo_list, List *joininfo_list)
+pred_test(List *predicate_list, List *restrictinfo_list, List *joininfo_list,
+                 int relvarno)
 {
        List       *pred;
 
@@ -978,6 +981,18 @@ pred_test(List *predicate_list, List *restrictinfo_list, List *joininfo_list)
                return false;                   /* no restriction clauses: the test must
                                                                 * fail */
 
+       /*
+        * The predicate as stored in the index definition will use varno 1
+        * for its Vars referencing the indexed relation.  If the indexed
+        * relation isn't varno 1 in the query, we must adjust the predicate
+        * to make the Vars match, else equal() won't work.
+        */
+       if (relvarno != 1)
+       {
+               predicate_list = copyObject(predicate_list);
+               ChangeVarNodes((Node *) predicate_list, 1, relvarno, 0);
+       }
+
        foreach(pred, predicate_list)
        {
                /*