*** pgsql/src/backend/optimizer/path/allpaths.c	2009/11/22 14:54:31	1.190
--- pgsql/src/backend/optimizer/path/allpaths.c	2009/11/28 00:46:19	1.191
***************
*** 8,14 ****
   *
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.189 2009/11/15 02:45:35 tgl Exp $
   *
   *-------------------------------------------------------------------------
   */
--- 8,14 ----
   *
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.190 2009/11/22 14:54:31 heikki Exp $
   *
   *-------------------------------------------------------------------------
   */
*************** make_rel_from_joinlist(PlannerInfo *root
*** 898,938 ****
  RelOptInfo *
  standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
  {
- 	List	  **joinitems;
  	int			lev;
  	RelOptInfo *rel;
  
  	/*
  	 * We employ a simple "dynamic programming" algorithm: we first find all
  	 * ways to build joins of two jointree items, then all ways to build joins
  	 * of three items (from two-item joins and single items), then four-item
  	 * joins, and so on until we have considered all ways to join all the
  	 * items into one rel.
  	 *
! 	 * joinitems[j] is a list of all the j-item rels.  Initially we set
! 	 * joinitems[1] to represent all the single-jointree-item relations.
  	 */
! 	joinitems = (List **) palloc0((levels_needed + 1) * sizeof(List *));
  
! 	joinitems[1] = initial_rels;
  
  	for (lev = 2; lev <= levels_needed; lev++)
  	{
! 		ListCell   *x;
  
  		/*
  		 * Determine all possible pairs of relations to be joined at this
  		 * level, and build paths for making each one from every available
  		 * pair of lower-level relations.
  		 */
! 		joinitems[lev] = join_search_one_level(root, lev, joinitems);
  
  		/*
  		 * Do cleanup work on each just-processed rel.
  		 */
! 		foreach(x, joinitems[lev])
  		{
! 			rel = (RelOptInfo *) lfirst(x);
  
  			/* Find and save the cheapest paths for this rel */
  			set_cheapest(rel);
--- 898,944 ----
  RelOptInfo *
  standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
  {
  	int			lev;
  	RelOptInfo *rel;
  
  	/*
+ 	 * This function cannot be invoked recursively within any one planning
+ 	 * problem, so join_rel_level[] can't be in use already.
+ 	 */
+ 	Assert(root->join_rel_level == NULL);
+ 
+ 	/*
  	 * We employ a simple "dynamic programming" algorithm: we first find all
  	 * ways to build joins of two jointree items, then all ways to build joins
  	 * of three items (from two-item joins and single items), then four-item
  	 * joins, and so on until we have considered all ways to join all the
  	 * items into one rel.
  	 *
! 	 * root->join_rel_level[j] is a list of all the j-item rels.  Initially we
! 	 * set root->join_rel_level[1] to represent all the single-jointree-item
! 	 * relations.
  	 */
! 	root->join_rel_level = (List **) palloc0((levels_needed + 1) * sizeof(List *));
  
! 	root->join_rel_level[1] = initial_rels;
  
  	for (lev = 2; lev <= levels_needed; lev++)
  	{
! 		ListCell   *lc;
  
  		/*
  		 * Determine all possible pairs of relations to be joined at this
  		 * level, and build paths for making each one from every available
  		 * pair of lower-level relations.
  		 */
! 		join_search_one_level(root, lev);
  
  		/*
  		 * Do cleanup work on each just-processed rel.
  		 */
! 		foreach(lc, root->join_rel_level[lev])
  		{
! 			rel = (RelOptInfo *) lfirst(lc);
  
  			/* Find and save the cheapest paths for this rel */
  			set_cheapest(rel);
*************** standard_join_search(PlannerInfo *root,
*** 946,956 ****
  	/*
  	 * We should have a single rel at the final level.
  	 */
! 	if (joinitems[levels_needed] == NIL)
  		elog(ERROR, "failed to build any %d-way joins", levels_needed);
! 	Assert(list_length(joinitems[levels_needed]) == 1);
  
! 	rel = (RelOptInfo *) linitial(joinitems[levels_needed]);
  
  	return rel;
  }
--- 952,964 ----
  	/*
  	 * We should have a single rel at the final level.
  	 */
! 	if (root->join_rel_level[levels_needed] == NIL)
  		elog(ERROR, "failed to build any %d-way joins", levels_needed);
! 	Assert(list_length(root->join_rel_level[levels_needed]) == 1);
! 
! 	rel = (RelOptInfo *) linitial(root->join_rel_level[levels_needed]);
  
! 	root->join_rel_level = NULL;
  
  	return rel;
  }