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Fix GEQO optimizer to work correctly with new outer-join-capable

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query representation.  Note that GEQO_RELS setting is now interpreted
as the number of top-level items in the FROM list, not necessarily the
number of relations in the query.  This seems appropriate since we are
only doing join-path searching over the top-level items.
This commit is contained in:
Tom Lane
2000-09-19 18:42:34 +00:00
parent 457ac0331c
commit ba2ea6e0f5
6 changed files with 57 additions and 48 deletions
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50
src/backend/optimizer/geqo/geqo_eval.c
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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $Id: geqo_eval.c,v 1.54 2000/09/12 21:06:50 tgl Exp $ * $Id: geqo_eval.c,v 1.55 2000/09/19 18:42:33 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -36,7 +36,7 @@
* Returns cost of a query tree as an individual of the population. * Returns cost of a query tree as an individual of the population.
*/ */
Cost Cost
geqo_eval(Query *root, Gene *tour, int num_gene) geqo_eval(Query *root, List *initial_rels, Gene *tour, int num_gene)
{ {
MemoryContext mycontext; MemoryContext mycontext;
MemoryContext oldcxt; MemoryContext oldcxt;
@ -64,7 +64,7 @@ geqo_eval(Query *root, Gene *tour, int num_gene)
savelist = root->join_rel_list; savelist = root->join_rel_list;
/* construct the best path for the given combination of relations */ /* construct the best path for the given combination of relations */
joinrel = gimme_tree(root, tour, 0, num_gene, NULL); joinrel = gimme_tree(root, initial_rels, tour, num_gene, 0, NULL);
/* /*
* compute fitness * compute fitness
@ -86,35 +86,42 @@ geqo_eval(Query *root, Gene *tour, int num_gene)
/* /*
* gimme_tree * gimme_tree
* this program presumes that only LEFT-SIDED TREES are considered! * this routine considers only LEFT-SIDED TREES!
* *
* 'old_rel' is the preceding join * 'root' is the Query
* 'initial_rels' is the list of initial relations (FROM-list items)
* 'tour' is the proposed join order, of length 'num_gene'
* 'rel_count' is number of initial_rels items already joined (initially 0)
* 'old_rel' is the preceding join (initially NULL)
* *
* Returns a new join relation incorporating all joins in a left-sided tree. * Returns a new join relation incorporating all joins in a left-sided tree.
*/ */
RelOptInfo * RelOptInfo *
gimme_tree(Query *root, Gene *tour, int rel_count, int num_gene, gimme_tree(Query *root, List *initial_rels,
RelOptInfo *old_rel) Gene *tour, int num_gene,
int rel_count, RelOptInfo *old_rel)
{ {
RelOptInfo *inner_rel; /* current relation */ RelOptInfo *inner_rel; /* current relation */
int base_rel_index; int init_rel_index;
if (rel_count < num_gene) if (rel_count < num_gene)
{ /* tree not yet finished */ {
/* tree not yet finished */
init_rel_index = (int) tour[rel_count];
/* tour[0] = 3; tour[1] = 1; tour[2] = 2 */ inner_rel = (RelOptInfo *) nth(init_rel_index - 1, initial_rels);
base_rel_index = (int) tour[rel_count];
inner_rel = (RelOptInfo *) nth(base_rel_index - 1, root->base_rel_list);
if (rel_count == 0) if (rel_count == 0)
{ /* processing first join with {
* base_rel_index = (int) tour[0] */ /* processing first join with init_rel_index = (int) tour[0] */
rel_count++; rel_count++;
return gimme_tree(root, tour, rel_count, num_gene, inner_rel); return gimme_tree(root, initial_rels,
tour, num_gene,
rel_count, inner_rel);
} }
else else
{ /* tree main part */ {
/* tree main part */
List *acceptable_rels = lcons(inner_rel, NIL); List *acceptable_rels = lcons(inner_rel, NIL);
List *new_rels; List *new_rels;
RelOptInfo *new_rel; RelOptInfo *new_rel;
@ -133,13 +140,14 @@ gimme_tree(Query *root, Gene *tour, int rel_count, int num_gene,
} }
new_rel = (RelOptInfo *) lfirst(new_rels); new_rel = (RelOptInfo *) lfirst(new_rels);
rel_count++;
Assert(length(new_rel->relids) == rel_count);
/* Find and save the cheapest paths for this rel */ /* Find and save the cheapest paths for this rel */
set_cheapest(new_rel); set_cheapest(new_rel);
return gimme_tree(root, tour, rel_count, num_gene, new_rel); /* and recurse... */
rel_count++;
return gimme_tree(root, initial_rels,
tour, num_gene,
rel_count, new_rel);
} }
} }

20
src/backend/optimizer/geqo/geqo_main.c
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $Id: geqo_main.c,v 1.23 2000/08/07 00:51:23 tgl Exp $ * $Id: geqo_main.c,v 1.24 2000/09/19 18:42:33 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -65,13 +65,12 @@ static int gimme_number_generations(int pool_size, int effort);
*/ */
RelOptInfo * RelOptInfo *
geqo(Query *root) geqo(Query *root, int number_of_rels, List *initial_rels)
{ {
int generation; int generation;
Chromosome *momma; Chromosome *momma;
Chromosome *daddy; Chromosome *daddy;
Chromosome *kid; Chromosome *kid;
int number_of_rels;
Pool *pool; Pool *pool;
int pool_size, int pool_size,
number_generations, number_generations,
@ -95,9 +94,6 @@ geqo(Query *root)
#endif #endif
/* set tour size */
number_of_rels = length(root->base_rel_list);
/* set GA parameters */ /* set GA parameters */
pool_size = gimme_pool_size(number_of_rels); pool_size = gimme_pool_size(number_of_rels);
number_generations = gimme_number_generations(pool_size, Geqo_effort); number_generations = gimme_number_generations(pool_size, Geqo_effort);
@ -114,7 +110,7 @@ geqo(Query *root)
pool = alloc_pool(pool_size, number_of_rels); pool = alloc_pool(pool_size, number_of_rels);
/* random initialization of the pool */ /* random initialization of the pool */
random_init_pool(root, pool, 0, pool->size); random_init_pool(root, initial_rels, pool, 0, pool->size);
/* sort the pool according to cheapest path as fitness */ /* sort the pool according to cheapest path as fitness */
sort_pool(pool); /* we have to do it only one time, since sort_pool(pool); /* we have to do it only one time, since
@ -204,7 +200,8 @@ geqo(Query *root)
/* EVALUATE FITNESS */ /* EVALUATE FITNESS */
kid->worth = geqo_eval(root, kid->string, pool->string_length); kid->worth = geqo_eval(root, initial_rels,
kid->string, pool->string_length);
/* push the kid into the wilderness of life according to its worth */ /* push the kid into the wilderness of life according to its worth */
spread_chromo(kid, pool); spread_chromo(kid, pool);
@ -247,9 +244,10 @@ geqo(Query *root)
best_tour = (Gene *) pool->data[0].string; best_tour = (Gene *) pool->data[0].string;
/* root->join_relation_list_ will be modified during this ! */ /* root->join_rel_list will be modified during this ! */
best_rel = (RelOptInfo *) gimme_tree(root, best_tour, 0, best_rel = (RelOptInfo *) gimme_tree(root, initial_rels,
pool->string_length, NULL); best_tour, pool->string_length,
0, NULL);
/* DBG: show the query plan /* DBG: show the query plan
print_plan(best_plan, root); print_plan(best_plan, root);

14
src/backend/optimizer/geqo/geqo_pool.c
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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $Id: geqo_pool.c,v 1.17 2000/01/26 05:56:33 momjian Exp $ * $Id: geqo_pool.c,v 1.18 2000/09/19 18:42:33 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -84,18 +84,18 @@ free_pool(Pool *pool)
* initialize genetic pool * initialize genetic pool
*/ */
void void
random_init_pool(Query *root, Pool *pool, int strt, int stp) random_init_pool(Query *root, List *initial_rels,
Pool *pool, int strt, int stp)
{ {
Chromosome *chromo = (Chromosome *) pool->data; Chromosome *chromo = (Chromosome *) pool->data;
int i; int i;
for (i = strt; i < stp; i++) for (i = strt; i < stp; i++)
{ {
init_tour(chromo[i].string, pool->string_length); /* from init_tour(chromo[i].string, pool->string_length);
* "geqo_recombination.c" pool->data[i].worth = geqo_eval(root, initial_rels,
* */ chromo[i].string,
pool->string_length);
pool->data[i].worth = geqo_eval(root, chromo[i].string, pool->string_length); /* "from geqo_eval.c" */
} }
} }

4
src/backend/optimizer/path/allpaths.c
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@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.63 2000/09/12 21:06:52 tgl Exp $ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.64 2000/09/19 18:42:34 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -188,7 +188,7 @@ make_one_rel_by_joins(Query *root, int levels_needed, List *initial_rels)
* rest will be skipped in case of GEQO * * rest will be skipped in case of GEQO *
*******************************************/ *******************************************/
if (enable_geqo && levels_needed >= geqo_rels) if (enable_geqo && levels_needed >= geqo_rels)
return geqo(root); return geqo(root, levels_needed, initial_rels);
/* /*
* We employ a simple "dynamic programming" algorithm: we first find * We employ a simple "dynamic programming" algorithm: we first find

12
src/include/optimizer/geqo.h
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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $Id: geqo.h,v 1.20 2000/06/28 03:33:22 tgl Exp $ * $Id: geqo.h,v 1.21 2000/09/19 18:42:32 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -62,11 +62,13 @@ extern int Geqo_random_seed; /* or negative to use current time */
/* routines in geqo_main.c */ /* routines in geqo_main.c */
extern RelOptInfo *geqo(Query *root); extern RelOptInfo *geqo(Query *root, int number_of_rels, List *initial_rels);
/* routines in geqo_eval.c */ /* routines in geqo_eval.c */
extern Cost geqo_eval(Query *root, Gene *tour, int num_gene); extern Cost geqo_eval(Query *root, List *initial_rels,
extern RelOptInfo *gimme_tree(Query *root, Gene *tour, int rel_count, Gene *tour, int num_gene);
int num_gene, RelOptInfo *old_rel); extern RelOptInfo *gimme_tree(Query *root, List *initial_rels,
Gene *tour, int num_gene,
int rel_count, RelOptInfo *old_rel);
#endif /* GEQO_H */ #endif /* GEQO_H */

5
src/include/optimizer/geqo_pool.h
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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $Id: geqo_pool.h,v 1.9 2000/01/26 05:58:20 momjian Exp $ * $Id: geqo_pool.h,v 1.10 2000/09/19 18:42:32 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -29,7 +29,8 @@
extern Pool *alloc_pool(int pool_size, int string_length); extern Pool *alloc_pool(int pool_size, int string_length);
extern void free_pool(Pool *pool); extern void free_pool(Pool *pool);
extern void random_init_pool(Query *root, Pool *pool, int strt, int stop); extern void random_init_pool(Query *root, List *initial_rels,
Pool *pool, int strt, int stop);
extern Chromosome *alloc_chromo(int string_length); extern Chromosome *alloc_chromo(int string_length);
extern void free_chromo(Chromosome *chromo); extern void free_chromo(Chromosome *chromo);