Clean up messy clause-selectivity code in clausesel.c; repair bug

identified by Hiroshi (incorrect cost attributed to OR clauses
after multiple passes through set_rest_selec()).  I think the code
was trying to allow selectivities of OR subclauses to be passed in
from outside, but noplace was actually passing any useful data, and
set_rest_selec() was passing wrong data.

Restructure representation of "indexqual" in IndexPath nodes so that
it is the same as for indxqual in completed IndexScan nodes: namely,
a toplevel list with an entry for each pass of the index scan, having
sublists that are implicitly-ANDed index qual conditions for that pass.
You don't want to know what the old representation was :-(

Improve documentation of OR-clause indexscan functions.

Remove useless 'notclause' field from RestrictInfo nodes.  (This might
force an initdb for anyone who has stored rules containing RestrictInfos,
but I do not think that RestrictInfo ever appears in completed plans.)

3 files changed, 6 insertions, 7 deletions

diff --git a/src/include/optimizer/clauses.h b/src/include/optimizer/clauses.h
index de135ca1d5..e362b7c64d 100644
--- a/src/include/optimizer/clauses.h
+++ b/src/include/optimizer/clauses.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: clauses.h,v 1.21 1999/07/15 23:03:57 momjian Exp $
+ * $Id: clauses.h,v 1.22 1999/07/24 23:21:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -34,13 +34,13 @@ extern Expr *get_notclausearg(Expr *notclause);
 
 extern bool and_clause(Node *clause);
 extern Expr *make_andclause(List *andclauses);
+extern Expr *make_ands_explicit(List *andclauses);
 
 extern bool case_clause(Node *clause);
 
 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);
-extern bool contains_not(Node *clause);
 extern bool is_joinable(Node *clause);
 extern bool qual_clause_p(Node *clause);
 extern void fix_opid(Node *clause);
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index b9fc710370..1dfe975226 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: cost.h,v 1.21 1999/07/15 15:21:20 momjian Exp $
+ * $Id: cost.h,v 1.22 1999/07/24 23:21:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,7 +59,6 @@ extern void set_clause_selectivities(List *restrictinfo_list, Cost new_selectivi
 extern Cost product_selec(List *restrictinfo_list);
 extern void set_rest_relselec(Query *root, List *rel_list);
 extern void set_rest_selec(Query *root, List *restrictinfo_list);
-extern Cost compute_clause_selec(Query *root,
-					 Node *clause, List *or_selectivities);
+extern Cost compute_clause_selec(Query *root, Node *clause);
 
 #endif	 /* COST_H */
diff --git a/src/include/optimizer/restrictinfo.h b/src/include/optimizer/restrictinfo.h
index 2f5c4dca20..7412ca46fa 100644
--- a/src/include/optimizer/restrictinfo.h
+++ b/src/include/optimizer/restrictinfo.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: restrictinfo.h,v 1.5 1999/07/15 15:21:23 momjian Exp $
+ * $Id: restrictinfo.h,v 1.6 1999/07/24 23:21:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,7 +15,7 @@
 
 #include "nodes/relation.h"
 
-extern bool valid_or_clause(RestrictInfo *restrictinfo);
+extern bool restriction_is_or_clause(RestrictInfo *restrictinfo);
 extern List *get_actual_clauses(List *restrictinfo_list);
 extern void get_relattvals(List *restrictinfo_list, List **attnos,
 			   List **values, List **flags);