diff options
Diffstat (limited to 'src/backend/optimizer/geqo/geqo_eval.c')
| -rw-r--r-- | src/backend/optimizer/geqo/geqo_eval.c | 50 |
1 files changed, 29 insertions, 21 deletions
diff --git a/src/backend/optimizer/geqo/geqo_eval.c b/src/backend/optimizer/geqo/geqo_eval.c index f32b0d64ee..1970ca9a43 100644 --- a/src/backend/optimizer/geqo/geqo_eval.c +++ b/src/backend/optimizer/geqo/geqo_eval.c @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc * 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. */ 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 oldcxt; @@ -64,7 +64,7 @@ geqo_eval(Query *root, Gene *tour, int num_gene) savelist = root->join_rel_list; /* 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 @@ -86,35 +86,42 @@ geqo_eval(Query *root, Gene *tour, int num_gene) /* * 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. */ RelOptInfo * -gimme_tree(Query *root, Gene *tour, int rel_count, int num_gene, - RelOptInfo *old_rel) +gimme_tree(Query *root, List *initial_rels, + Gene *tour, int num_gene, + int rel_count, RelOptInfo *old_rel) { RelOptInfo *inner_rel; /* current relation */ - int base_rel_index; + int init_rel_index; 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 */ - base_rel_index = (int) tour[rel_count]; - - inner_rel = (RelOptInfo *) nth(base_rel_index - 1, root->base_rel_list); + inner_rel = (RelOptInfo *) nth(init_rel_index - 1, initial_rels); 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++; - 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 - { /* tree main part */ + { + /* tree main part */ List *acceptable_rels = lcons(inner_rel, NIL); List *new_rels; 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); - rel_count++; - Assert(length(new_rel->relids) == rel_count); - /* Find and save the cheapest paths for this 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); } } |