3 files changed, 53 insertions, 6 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 841d85f7397..34747d0f971 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.250 2009/01/01 17:23:44 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.251 2009/01/09 15:46:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2576,3 +2576,39 @@ get_column_info_for_window(PlannerInfo *root, WindowClause *wc, List *tlist,
 			elog(ERROR, "failed to deconstruct sort operators into partitioning/ordering operators");
 	}
 }
+
+
+/*
+ * expression_planner
+ *		Perform planner's transformations on a standalone expression.
+ *
+ * Various utility commands need to evaluate expressions that are not part
+ * of a plannable query.  They can do so using the executor's regular
+ * expression-execution machinery, but first the expression has to be fed
+ * through here to transform it from parser output to something executable.
+ *
+ * Currently, we disallow sublinks in standalone expressions, so there's no
+ * real "planning" involved here.  (That might not always be true though.)
+ * What we must do is run eval_const_expressions to ensure that any function
+ * default arguments get inserted.  The fact that constant subexpressions
+ * get simplified is a side-effect that is useful when the expression will
+ * get evaluated more than once.  Also, we must fix operator function IDs.
+ *
+ * Note: this must not make any damaging changes to the passed-in expression
+ * tree.  (It would actually be okay to apply fix_opfuncids to it, but since
+ * we first do an expression_tree_mutator-based walk, what is returned will
+ * be a new node tree.)
+ */
+Expr *
+expression_planner(Expr *expr)
+{
+	Node	   *result;
+
+	/* Insert default arguments and simplify constant subexprs */
+	result = eval_const_expressions(NULL, (Node *) expr);
+
+	/* Fill in opfuncid values if missing */
+	fix_opfuncids(result);
+
+	return (Expr *) result;
+}
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index a0205d7b8c6..65c9b614584 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.274 2009/01/06 01:23:21 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.275 2009/01/09 15:46:10 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -2018,6 +2018,9 @@ rowtype_field_matches(Oid rowtypeid, int fieldnum,
  *
  * NOTE: the planner assumes that this will always flatten nested AND and
  * OR clauses into N-argument form.  See comments in prepqual.c.
+ *
+ * NOTE: another critical effect is that any function calls that require
+ * default arguments will be expanded.
  *--------------------
  */
 Node *
@@ -3854,10 +3857,14 @@ evaluate_expr(Expr *expr, Oid result_type, int32 result_typmod)
 	/* We can use the estate's working context to avoid memory leaks. */
 	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 
+	/* Make sure any opfuncids are filled in. */
+	fix_opfuncids((Node *) expr);
+
 	/*
-	 * Prepare expr for execution.
+	 * Prepare expr for execution.  (Note: we can't use ExecPrepareExpr
+	 * because it'd result in recursively invoking eval_const_expressions.)
 	 */
-	exprstate = ExecPrepareExpr(expr, estate);
+	exprstate = ExecInitExpr(expr, NULL);
 
 	/*
 	 * And evaluate it.
diff --git a/src/backend/optimizer/util/predtest.c b/src/backend/optimizer/util/predtest.c
index 4bbcb2fe229..678f560978d 100644
--- a/src/backend/optimizer/util/predtest.c
+++ b/src/backend/optimizer/util/predtest.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.23 2009/01/01 17:23:45 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.24 2009/01/09 15:46:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,6 +22,7 @@
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
+#include "optimizer/planmain.h"
 #include "optimizer/predtest.h"
 #include "utils/array.h"
 #include "utils/inval.h"
@@ -1405,8 +1406,11 @@ btree_predicate_proof(Expr *predicate, Node *clause, bool refute_it)
 							  (Expr *) pred_const,
 							  (Expr *) clause_const);
 
+	/* Fill in opfuncids */
+	fix_opfuncids((Node *) test_expr);
+
 	/* Prepare it for execution */
-	test_exprstate = ExecPrepareExpr(test_expr, estate);
+	test_exprstate = ExecInitExpr(test_expr, NULL);
 
 	/* And execute it. */
 	test_result = ExecEvalExprSwitchContext(test_exprstate,