Subselects in FROM clause, per ISO syntax: FROM (SELECT ...) [AS] alias.

(Don't forget that an alias is required.)  Views reimplemented as expanding
to subselect-in-FROM.  Grouping, aggregates, DISTINCT in views actually
work now (he says optimistically).  No UNION support in subselects/views
yet, but I have some ideas about that.  Rule-related permissions checking
moved out of rewriter and into executor.
INITDB REQUIRED!

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 1.39 2000/09/12 21:07:11 tgl Exp $
+ * $Id: clauses.h,v 1.40 2000/09/29 18:21:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,6 +43,7 @@ extern Expr *get_notclausearg(Expr *notclause);
 
 extern bool and_clause(Node *clause);
 extern Expr *make_andclause(List *andclauses);
+extern Node *make_and_qual(Node *qual1, Node *qual2);
 extern Expr *make_ands_explicit(List *andclauses);
 extern List *make_ands_implicit(Expr *clause);
 
@@ -56,10 +57,7 @@ extern void check_subplans_for_ungrouped_vars(Node *clause, Query *query);
 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 List *pull_constant_clauses(List *quals, List **constantQual);
 
 extern void clause_get_relids_vars(Node *clause, Relids *relids, List **vars);
 extern int	NumRelids(Node *clause);

src/include/optimizer/pathnode.h

@@ -1,13 +1,13 @@
 /*-------------------------------------------------------------------------
  *
  * pathnode.h
- *	  prototypes for pathnode.c, indexnode.c, relnode.c.
+ *	  prototypes for pathnode.c, relnode.c.
  *
  *
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pathnode.h,v 1.28 2000/09/12 21:07:11 tgl Exp $
+ * $Id: pathnode.h,v 1.29 2000/09/29 18:21:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,6 +32,7 @@ extern IndexPath *create_index_path(Query *root, RelOptInfo *rel,
 				  List *restriction_clauses,
 				  ScanDirection indexscandir);
 extern TidPath *create_tidscan_path(RelOptInfo *rel, List *tideval);
+extern Path *create_subqueryscan_path(RelOptInfo *rel);
 
 extern NestPath *create_nestloop_path(RelOptInfo *joinrel,
 									  JoinType jointype,
@@ -66,9 +67,4 @@ extern RelOptInfo *get_join_rel(Query *root, RelOptInfo *outer_rel,
 			 RelOptInfo *inner_rel,
 			 List **restrictlist_ptr);
 
-/*
- * prototypes for indexnode.h
- */
-extern List *find_relation_indices(Query *root, RelOptInfo *rel);
-
 #endif	 /* PATHNODE_H */

src/include/optimizer/paths.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: paths.h,v 1.47 2000/09/12 21:07:11 tgl Exp $
+ * $Id: paths.h,v 1.48 2000/09/29 18:21:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -28,6 +28,7 @@ extern bool enable_geqo;
 extern int	geqo_rels;
 
 extern RelOptInfo *make_one_rel(Query *root);
+extern RelOptInfo *make_fromexpr_rel(Query *root, FromExpr *from);
 
 /*
  * indxpath.c
@@ -77,7 +78,7 @@ extern List *make_rels_by_clause_joins(Query *root,
 extern List *make_rels_by_clauseless_joins(Query *root,
 										   RelOptInfo *old_rel,
 										   List *other_rels);
-extern RelOptInfo *make_rel_from_jointree(Query *root, Node *jtnode);
+extern RelOptInfo *make_jointree_rel(Query *root, Node *jtnode);
 
 /*
  * pathkeys.c

src/include/optimizer/plancat.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: plancat.h,v 1.19 2000/06/09 03:17:11 tgl Exp $
+ * $Id: plancat.h,v 1.20 2000/09/29 18:21:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,10 +17,10 @@
 #include "nodes/relation.h"
 
 
-extern void relation_info(Query *root, Index relid,
-			  bool *hasindex, long *pages, double *tuples);
+extern void relation_info(Oid relationObjectId,
+						  bool *hasindex, long *pages, double *tuples);
 
-extern List *find_secondary_indexes(Query *root, Index relid);
+extern List *find_secondary_indexes(Oid relationObjectId);
 
 extern List *find_inheritance_children(Oid inhparent);
 

src/include/optimizer/planmain.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: planmain.h,v 1.44 2000/09/12 21:07:11 tgl Exp $
+ * $Id: planmain.h,v 1.45 2000/09/29 18:21:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,8 +40,7 @@ extern Result *make_result(List *tlist, Node *resconstantqual, Plan *subplan);
  * prototypes for plan/initsplan.c
  */
 extern void build_base_rel_tlists(Query *root, List *tlist);
-extern Relids add_join_quals_to_rels(Query *root, Node *jtnode);
-extern void add_restrict_and_join_to_rels(Query *root, List *clauses);
+extern Relids distribute_quals_to_rels(Query *root, Node *jtnode);
 extern List *add_missing_rels_to_query(Query *root, Node *jtnode);
 extern void process_implied_equality(Query *root, Node *item1, Node *item2,
 									 Oid sortop1, Oid sortop2);