Clean up handling of variable-free qual clauses. System now does the

right thing with variable-free clauses that contain noncachable functions,
such as 'WHERE random() < 0.5' --- these are evaluated once per
potential output tuple.  Expressions that contain only Params are
now candidates to be indexscan quals --- for example, 'var = ($1 + 1)'
can now be indexed.  Cope with RelabelType nodes atop potential indexscan
variables --- this oversight prevents 7.0.* from recognizing some
potentially indexscanable situations.

4 files changed, 25 insertions, 18 deletions

diff --git a/src/include/executor/nodeNestloop.h b/src/include/executor/nodeNestloop.h
index b1242b0da0d..42e3fae8335 100644
--- a/src/include/executor/nodeNestloop.h
+++ b/src/include/executor/nodeNestloop.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodeNestloop.h,v 1.12 2000/01/26 05:58:05 momjian Exp $
+ * $Id: nodeNestloop.h,v 1.13 2000/08/13 02:50:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,7 +16,7 @@
 
 #include "nodes/plannodes.h"
 
-extern TupleTableSlot *ExecNestLoop(NestLoop *node, Plan *parent);
+extern TupleTableSlot *ExecNestLoop(NestLoop *node);
 extern bool ExecInitNestLoop(NestLoop *node, EState *estate, Plan *parent);
 extern int	ExecCountSlotsNestLoop(NestLoop *node);
 extern void ExecEndNestLoop(NestLoop *node);
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index a9ef6e78ae3..6e691c1d786 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.45 2000/08/06 04:26:29 tgl Exp $
+ * $Id: execnodes.h,v 1.46 2000/08/13 02:50:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -380,6 +380,7 @@ typedef struct CommonScanState
  *		NumScanKeys		   array of no of keys in each Skey struct
  *		RuntimeKeyInfo	   array of array of flags for Skeys evaled at runtime
  *		RuntimeContext	   expr context for evaling runtime Skeys
+ *		RuntimeKeysReady   true if runtime Skeys have been computed
  *		RelationDescs	   ptr to array of relation descriptors
  *		ScanDescs		   ptr to array of scan descriptors
  * ----------------
@@ -394,6 +395,7 @@ typedef struct IndexScanState
 	int		   *iss_NumScanKeys;
 	int		  **iss_RuntimeKeyInfo;
 	ExprContext *iss_RuntimeContext;
+	bool		iss_RuntimeKeysReady;
 	RelationPtr iss_RelationDescs;
 	IndexScanDescPtr iss_ScanDescs;
 	HeapTupleData iss_htup;
diff --git a/src/include/optimizer/clauses.h b/src/include/optimizer/clauses.h
index 946a9b0586f..1b2bcd92055 100644
--- a/src/include/optimizer/clauses.h
+++ b/src/include/optimizer/clauses.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: clauses.h,v 1.37 2000/05/30 04:24:57 tgl Exp $
+ * $Id: clauses.h,v 1.38 2000/08/13 02:50:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,7 +53,13 @@ extern bool contain_subplans(Node *clause);
 extern List *pull_subplans(Node *clause);
 extern void check_subplans_for_ungrouped_vars(Node *clause, Query *query);
 
-extern List *pull_constant_clauses(List *quals, List **constantQual);
+extern bool contain_noncachable_functions(Node *clause);
+
+extern bool is_pseudo_constant_clause(Node *clause);
+
+extern List *pull_constant_clauses(List *quals,
+								   List **noncachableQual,
+								   List **constantQual);
 
 extern void clause_get_relids_vars(Node *clause, Relids *relids, List **vars);
 extern int	NumRelids(Node *clause);
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 5c6c09ccbc3..9c105576ae2 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lsyscache.h,v 1.24 2000/06/08 22:37:58 momjian Exp $
+ * $Id: lsyscache.h,v 1.25 2000/08/13 02:50:31 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,7 +15,7 @@
 
 #include "access/htup.h"
 
-extern bool op_class(Oid opid, Oid opclass, Oid amopid);
+extern bool op_class(Oid opno, Oid opclass, Oid amopid);
 extern char *get_attname(Oid relid, AttrNumber attnum);
 extern AttrNumber get_attnum(Oid relid, char *attname);
 extern Oid	get_atttype(Oid relid, AttrNumber attnum);
@@ -23,21 +23,20 @@ extern bool get_attisset(Oid relid, char *attname);
 extern int32 get_atttypmod(Oid relid, AttrNumber attnum);
 extern double get_attdisbursion(Oid relid, AttrNumber attnum,
 				  double min_estimate);
-extern RegProcedure get_opcode(Oid opid);
-extern char *get_opname(Oid opid);
-extern bool op_mergejoinable(Oid opid, Oid ltype, Oid rtype,
+extern RegProcedure get_opcode(Oid opno);
+extern char *get_opname(Oid opno);
+extern bool op_mergejoinable(Oid opno, Oid ltype, Oid rtype,
 				 Oid *leftOp, Oid *rightOp);
-extern Oid	op_hashjoinable(Oid opid, Oid ltype, Oid rtype);
-extern Oid	get_commutator(Oid opid);
+extern Oid	op_hashjoinable(Oid opno, Oid ltype, Oid rtype);
+extern bool op_iscachable(Oid opno);
 extern HeapTuple get_operator_tuple(Oid opno);
-extern Oid	get_negator(Oid opid);
-extern RegProcedure get_oprrest(Oid opid);
-extern RegProcedure get_oprjoin(Oid opid);
+extern Oid	get_commutator(Oid opno);
+extern Oid	get_negator(Oid opno);
+extern RegProcedure get_oprrest(Oid opno);
+extern RegProcedure get_oprjoin(Oid opno);
 extern Oid	get_func_rettype(Oid funcid);
+extern bool func_iscachable(Oid funcid);
 extern char *get_rel_name(Oid relid);
-extern struct varlena *get_relstub(Oid relid, int no, bool *islast);
-extern Oid	get_ruleid(char *rulename);
-extern Oid	get_eventrelid(Oid ruleid);
 extern int16 get_typlen(Oid typid);
 extern bool get_typbyval(Oid typid);
 extern Datum get_typdefault(Oid typid);