database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-14 08:21:07 +03:00
Code Activity

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

Browse Source
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
Download Patch File Download Diff File Expand all files Collapse all files

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;
}
/*****************************************************************************