diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 4a0a1012c0a3836d1e454bcfa76d74c86a41ca78..e8e5b2ecb2d81fdcadc69df4658551f8c20f28de 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.183 2009/06/11 14:48:58 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.184 2009/07/06 18:26:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -29,6 +29,7 @@
#include "optimizer/plancat.h"
#include "optimizer/planner.h"
#include "optimizer/prep.h"
+#include "optimizer/restrictinfo.h"
#include "optimizer/var.h"
#include "parser/parse_clause.h"
#include "parser/parsetree.h"
@@ -318,6 +319,8 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
int childRTindex;
RangeTblEntry *childRTE;
RelOptInfo *childrel;
+ List *childquals;
+ Node *childqual;
Path *childpath;
ListCell *parentvars;
ListCell *childvars;
@@ -342,10 +345,34 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
* baserestrictinfo quals are needed before we can check for
* constraint exclusion; so do that first and then check to see if we
* can disregard this child.
+ *
+ * As of 8.4, the child rel's targetlist might contain non-Var
+ * expressions, which means that substitution into the quals
+ * could produce opportunities for const-simplification, and perhaps
+ * even pseudoconstant quals. To deal with this, we strip the
+ * RestrictInfo nodes, do the substitution, do const-simplification,
+ * and then reconstitute the RestrictInfo layer.
*/
- childrel->baserestrictinfo = (List *)
- adjust_appendrel_attrs((Node *) rel->baserestrictinfo,
- appinfo);
+ childquals = get_all_actual_clauses(rel->baserestrictinfo);
+ childquals = (List *) adjust_appendrel_attrs((Node *) childquals,
+ appinfo);
+ childqual = eval_const_expressions(root, (Node *)
+ make_ands_explicit(childquals));
+ if (childqual && IsA(childqual, Const) &&
+ (((Const *) childqual)->constisnull ||
+ !DatumGetBool(((Const *) childqual)->constvalue)))
+ {
+ /*
+ * Restriction reduces to constant FALSE or constant NULL after
+ * substitution, so this child need not be scanned.
+ */
+ set_dummy_rel_pathlist(childrel);
+ continue;
+ }
+ childquals = make_ands_implicit((Expr *) childqual);
+ childquals = make_restrictinfos_from_actual_clauses(root,
+ childquals);
+ childrel->baserestrictinfo = childquals;
if (relation_excluded_by_constraints(root, childrel, childRTE))
{
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index b5e10a91801e235121e1979d88fc54887a13ac3e..956b9559f821436caf044e5a711a3b9e97d8d7fa 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -22,7 +22,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.171 2009/06/11 14:48:59 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.172 2009/07/06 18:26:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1636,57 +1636,7 @@ adjust_appendrel_attrs_mutator(Node *node, AppendRelInfo *context)
Assert(!IsA(node, SpecialJoinInfo));
Assert(!IsA(node, AppendRelInfo));
Assert(!IsA(node, PlaceHolderInfo));
-
- /*
- * We have to process RestrictInfo nodes specially.
- */
- if (IsA(node, RestrictInfo))
- {
- RestrictInfo *oldinfo = (RestrictInfo *) node;
- RestrictInfo *newinfo = makeNode(RestrictInfo);
-
- /* Copy all flat-copiable fields */
- memcpy(newinfo, oldinfo, sizeof(RestrictInfo));
-
- /* Recursively fix the clause itself */
- newinfo->clause = (Expr *)
- adjust_appendrel_attrs_mutator((Node *) oldinfo->clause, context);
-
- /* and the modified version, if an OR clause */
- newinfo->orclause = (Expr *)
- adjust_appendrel_attrs_mutator((Node *) oldinfo->orclause, context);
-
- /* adjust relid sets too */
- newinfo->clause_relids = adjust_relid_set(oldinfo->clause_relids,
- context->parent_relid,
- context->child_relid);
- newinfo->required_relids = adjust_relid_set(oldinfo->required_relids,
- context->parent_relid,
- context->child_relid);
- newinfo->left_relids = adjust_relid_set(oldinfo->left_relids,
- context->parent_relid,
- context->child_relid);
- newinfo->right_relids = adjust_relid_set(oldinfo->right_relids,
- context->parent_relid,
- context->child_relid);
-
- /*
- * Reset cached derivative fields, since these might need to have
- * different values when considering the child relation.
- */
- newinfo->eval_cost.startup = -1;
- newinfo->norm_selec = -1;
- newinfo->outer_selec = -1;
- newinfo->left_ec = NULL;
- newinfo->right_ec = NULL;
- newinfo->left_em = NULL;
- newinfo->right_em = NULL;
- newinfo->scansel_cache = NIL;
- newinfo->left_bucketsize = -1;
- newinfo->right_bucketsize = -1;
-
- return (Node *) newinfo;
- }
+ Assert(!IsA(node, RestrictInfo));
/*
* NOTE: we do not need to recurse into sublinks, because they should
diff --git a/src/backend/optimizer/util/restrictinfo.c b/src/backend/optimizer/util/restrictinfo.c
index 47086a4bfcab6bb2cfc7f458358c772420c6c3d6..bb06694c8a571f8b6b29885504cc2e8f150c5bbf 100644
--- a/src/backend/optimizer/util/restrictinfo.c
+++ b/src/backend/optimizer/util/restrictinfo.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.60 2009/06/11 14:48:59 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.61 2009/07/06 18:26:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -271,6 +271,57 @@ make_restrictinfo_from_bitmapqual(Path *bitmapqual,
return result;
}
+/*
+ * make_restrictinfos_from_actual_clauses
+ *
+ * Given a list of implicitly-ANDed restriction clauses, produce a list
+ * of RestrictInfo nodes. This is used to reconstitute the RestrictInfo
+ * representation after doing transformations of a list of clauses.
+ *
+ * We assume that the clauses are relation-level restrictions and therefore
+ * we don't have to worry about is_pushed_down, outerjoin_delayed, or
+ * nullable_relids (these can be assumed true, false, and NULL, respectively).
+ * We do take care to recognize pseudoconstant clauses properly.
+ */
+List *
+make_restrictinfos_from_actual_clauses(PlannerInfo *root,
+ List *clause_list)
+{
+ List *result = NIL;
+ ListCell *l;
+
+ foreach(l, clause_list)
+ {
+ Expr *clause = (Expr *) lfirst(l);
+ bool pseudoconstant;
+ RestrictInfo *rinfo;
+
+ /*
+ * It's pseudoconstant if it contains no Vars and no volatile
+ * functions. We probably can't see any sublinks here, so
+ * contain_var_clause() would likely be enough, but for safety
+ * use contain_vars_of_level() instead.
+ */
+ pseudoconstant =
+ !contain_vars_of_level((Node *) clause, 0) &&
+ !contain_volatile_functions((Node *) clause);
+ if (pseudoconstant)
+ {
+ /* tell createplan.c to check for gating quals */
+ root->hasPseudoConstantQuals = true;
+ }
+
+ rinfo = make_restrictinfo(clause,
+ true,
+ false,
+ pseudoconstant,
+ NULL,
+ NULL);
+ result = lappend(result, rinfo);
+ }
+ return result;
+}
+
/*
* make_restrictinfo_internal
*
@@ -481,6 +532,31 @@ get_actual_clauses(List *restrictinfo_list)
return result;
}
+/*
+ * get_all_actual_clauses
+ *
+ * Returns a list containing the bare clauses from 'restrictinfo_list'.
+ *
+ * This loses the distinction between regular and pseudoconstant clauses,
+ * so be careful what you use it for.
+ */
+List *
+get_all_actual_clauses(List *restrictinfo_list)
+{
+ List *result = NIL;
+ ListCell *l;
+
+ foreach(l, restrictinfo_list)
+ {
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+
+ Assert(IsA(rinfo, RestrictInfo));
+
+ result = lappend(result, rinfo->clause);
+ }
+ return result;
+}
+
/*
* extract_actual_clauses
*
diff --git a/src/include/optimizer/restrictinfo.h b/src/include/optimizer/restrictinfo.h
index dcdc82ee1dc4acc9c6006a84c838b70730f94bcb..43de403758e3c04de4e1ae59a9fd559f4ee3bfe1 100644
--- a/src/include/optimizer/restrictinfo.h
+++ b/src/include/optimizer/restrictinfo.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.44 2009/05/09 22:51:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.45 2009/07/06 18:26:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -30,8 +30,11 @@ extern RestrictInfo *make_restrictinfo(Expr *clause,
extern List *make_restrictinfo_from_bitmapqual(Path *bitmapqual,
bool is_pushed_down,
bool include_predicates);
+extern List *make_restrictinfos_from_actual_clauses(PlannerInfo *root,
+ List *clause_list);
extern bool restriction_is_or_clause(RestrictInfo *restrictinfo);
extern List *get_actual_clauses(List *restrictinfo_list);
+extern List *get_all_actual_clauses(List *restrictinfo_list);
extern List *extract_actual_clauses(List *restrictinfo_list,
bool pseudoconstant);
extern void extract_actual_join_clauses(List *restrictinfo_list,