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Remove some recursion in optimizer and clean up some code there.

This commit is contained in:
Bruce Momjian 1997-12-21 05:18:48 +00:00
parent 0808e658a7
commit 78a055a659
4 changed files with 129 additions and 122 deletions
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170
src/backend/optimizer/path/allpaths.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.13 1997/09/08 21:44:44 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.14 1997/12/21 05:18:18 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -44,7 +44,7 @@ int32 _use_geqo_rels_ = GEQO_RELS;
static void find_rel_paths(Query *root, List *rels);
static List *find_join_paths(Query *root, List *outer_rels, int levels_left);
static List *find_join_paths(Query *root, List *outer_rels, int levels_needed);
/*
* find-paths--
@ -56,14 +56,14 @@ static List *find_join_paths(Query *root, List *outer_rels, int levels_left);
List *
find_paths(Query *root, List *rels)
{
int levels_left;
int levels_needed;
/*
* Set the number of join (not nesting) levels yet to be processed.
*/
levels_left = length(rels);
levels_needed = length(rels);
if (levels_left <= 0)
if (levels_needed <= 0)
return NIL;
/*
@ -71,13 +71,13 @@ find_paths(Query *root, List *rels)
*/
find_rel_paths(root, rels);
if (levels_left <= 1)
if (levels_needed <= 1)
{
/*
* Unsorted single relation, no more processing is required.
*/
return (rels);
return rels;
}
else
{
@ -88,7 +88,7 @@ find_paths(Query *root, List *rels)
*/
set_rest_relselec(root, rels);
return (find_join_paths(root, rels, levels_left - 1));
return find_join_paths(root, rels, levels_needed);
}
}
@ -165,17 +165,16 @@ find_rel_paths(Query *root, List *rels)
* 'outer-rels' is the current list of relations for which join paths
* are to be found, i.e., he current list of relations that
* have already been derived.
* 'levels-left' is the current join level being processed, where '1' is
* the "last" level
* 'levels-needed' is the number of iterations needed
*
* Returns the final level of join relations, i.e., the relation that is
* the result of joining all the original relations togehter.
* the result of joining all the original relations together.
*/
static List *
find_join_paths(Query *root, List *outer_rels, int levels_left)
find_join_paths(Query *root, List *outer_rels, int levels_needed)
{
List *x;
List *new_rels;
List *new_rels = NIL;
Rel *rel;
/*******************************************
@ -190,89 +189,84 @@ find_join_paths(Query *root, List *outer_rels, int levels_left)
* rest will be deprecated in case of GEQO *
*******************************************/
/*
* Determine all possible pairs of relations to be joined at this
* level. Determine paths for joining these relation pairs and modify
* 'new-rels' accordingly, then eliminate redundant join relations.
*/
new_rels = find_join_rels(root, outer_rels);
find_all_join_paths(root, new_rels);
new_rels = prune_joinrels(new_rels);
while (--levels_needed)
{
/*
* Determine all possible pairs of relations to be joined at this
* level. Determine paths for joining these relation pairs and modify
* 'new-rels' accordingly, then eliminate redundant join relations.
*/
new_rels = find_join_rels(root, outer_rels);
find_all_join_paths(root, new_rels);
prune_joinrels(new_rels);
#if 0
/*
* * for each expensive predicate in each path in each distinct rel, *
* consider doing pullup -- JMH
*/
if (XfuncMode != XFUNC_NOPULL && XfuncMode != XFUNC_OFF)
/*
* * for each expensive predicate in each path in each distinct rel, *
* consider doing pullup -- JMH
*/
if (XfuncMode != XFUNC_NOPULL && XfuncMode != XFUNC_OFF)
foreach(x, new_rels)
xfunc_trypullup((Rel *) lfirst(x));
#endif
prune_rel_paths(new_rels);
if (BushyPlanFlag)
{
/*
* In case of bushy trees if there is still a join between a join
* relation and another relation, add a new joininfo that involves
* the join relation to the joininfo list of the other relation
*/
add_new_joininfos(root, new_rels, outer_rels);
}
foreach(x, new_rels)
xfunc_trypullup((Rel *) lfirst(x));
#endif
prune_rel_paths(new_rels);
if (BushyPlanFlag)
{
/*
* In case of bushy trees if there is still a join between a join
* relation and another relation, add a new joininfo that involves
* the join relation to the joininfo list of the other relation
*/
add_new_joininfos(root, new_rels, outer_rels);
}
foreach(x, new_rels)
{
rel = (Rel *) lfirst(x);
if (rel->size <= 0)
rel->size = compute_rel_size(rel);
rel->width = compute_rel_width(rel);
/*#define OPTIMIZER_DEBUG*/
{
rel = (Rel *) lfirst(x);
if (rel->size <= 0)
rel->size = compute_rel_size(rel);
rel->width = compute_rel_width(rel);
/*#define OPTIMIZER_DEBUG*/
#ifdef OPTIMIZER_DEBUG
printf("levels left: %d\n", levels_left);
debug_print_rel(root, rel);
printf("levels left: %d\n", levels_left);
debug_print_rel(root, rel);
#endif
}
if (BushyPlanFlag)
{
/*
* prune rels that have been completely incorporated into new join
* rels
*/
outer_rels = prune_oldrels(outer_rels);
/*
* merge join rels if then contain the same list of base rels
*/
outer_rels = merge_joinrels(new_rels, outer_rels);
root->join_relation_list_ = outer_rels;
}
else
{
root->join_relation_list_ = new_rels;
}
if (!BushyPlanFlag)
outer_rels = new_rels;
}
if (BushyPlanFlag)
{
/*
* prune rels that have been completely incorporated into new join
* rels
*/
outer_rels = prune_oldrels(outer_rels);
/*
* merge join rels if then contain the same list of base rels
*/
outer_rels = merge_joinrels(new_rels, outer_rels);
root->join_relation_list_ = outer_rels;
}
return final_join_rels(outer_rels);
else
{
root->join_relation_list_ = new_rels;
}
if (levels_left == 1)
{
if (BushyPlanFlag)
return (final_join_rels(outer_rels));
else
return (new_rels);
}
else
{
if (BushyPlanFlag)
return (find_join_paths(root, outer_rels, levels_left - 1));
else
return (find_join_paths(root, new_rels, levels_left - 1));
}
return new_rels;
}
/*****************************************************************************

65
src/backend/optimizer/path/prune.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/Attic/prune.c,v 1.6 1997/09/08 21:45:08 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/Attic/prune.c,v 1.7 1997/12/21 05:18:21 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -29,23 +29,21 @@ static List *prune_joinrel(Rel *rel, List *other_rels);
/*
* prune-joinrels--
* Removes any redundant relation entries from a list of rel nodes
* 'rel-list'.
* 'rel-list'. Obviosly, the first relation can't be a duplicate.
*
* Returns the resulting list.
*
*/
List *
void
prune_joinrels(List *rel_list)
{
List *temp_list = NIL;
List *i;
if (rel_list != NIL)
{
temp_list = lcons(lfirst(rel_list),
prune_joinrels(prune_joinrel((Rel *) lfirst(rel_list),
lnext(rel_list))));
}
return (temp_list);
/*
* rel_list can shorten while running as duplicate relations are deleted
*/
foreach(i, rel_list)
lnext(i) = prune_joinrel((Rel *) lfirst(i), lnext(i));
}
/*
@ -62,28 +60,39 @@ prune_joinrels(List *rel_list)
static List *
prune_joinrel(Rel *rel, List *other_rels)
{
List *i = NIL;
List *t_list = NIL;
List *temp_node = NIL;
Rel *other_rel = (Rel *) NULL;
List *cur = NIL;
List *return_list = NIL;
foreach(i, other_rels)
/* find first relation that doesn't match */
foreach(cur, other_rels)
{
other_rel = (Rel *) lfirst(i);
if (same(rel->relids, other_rel->relids))
Rel *other_rel = (Rel *) lfirst(cur);
if (!same(rel->relids, other_rel->relids))
break;
}
/* we now know cur doesn't match, or is NIL */
return_list = cur;
/* remove relations that do match, we use lnext so we can remove easily */
if (cur != NIL)
{
while (lnext(cur) != NIL)
{
rel->pathlist = add_pathlist(rel,
rel->pathlist,
other_rel->pathlist);
t_list = nconc(t_list, NIL); /* XXX is this right ? */
}
else
{
temp_node = lcons(other_rel, NIL);
t_list = nconc(t_list, temp_node);
Rel *other_rel = (Rel *) lfirst(lnext(cur));
if (same(rel->relids, other_rel->relids))
{
rel->pathlist = add_pathlist(rel,
rel->pathlist,
other_rel->pathlist);
lnext(cur) = lnext(lnext(cur)); /* delete it */
}
cur = lnext(cur);
}
}
return (t_list);
return return_list;
}
/*

12
src/backend/optimizer/prep/prepunion.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.11 1997/12/20 07:59:33 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.12 1997/12/21 05:18:28 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -236,9 +236,13 @@ plan_union_query(List *relids,
new_root->uniqueFlag = NULL;
new_root->sortClause = NULL;
new_root->groupClause = NULL;
new_root->qry_numAgg = 0;
new_root->qry_aggs = NULL;
del_agg_tlist_references(new_root->targetList);
if (new_root->qry_numAgg != 0)
{
new_root->qry_numAgg = 0;
pfree(new_root->qry_aggs);
new_root->qry_aggs = NULL;
del_agg_tlist_references(new_root->targetList);
}
fix_parsetree_attnums(rt_index,
rt_entry->relid,
relid,

4
src/include/optimizer/paths.h
View File

@ -7,7 +7,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: paths.h,v 1.5 1997/11/26 01:13:47 momjian Exp $
* $Id: paths.h,v 1.6 1997/12/21 05:18:48 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -92,7 +92,7 @@ extern List *final_join_rels(List *join_rel_list);
/*
* prototypes for path/prune.c
*/
extern List *prune_joinrels(List *rel_list);
extern void prune_joinrels(List *rel_list);
extern void prune_rel_paths(List *rel_list);
extern Path *prune_rel_path(Rel *rel, Path *unorderedpath);
extern List *merge_joinrels(List *rel_list1, List *rel_list2);