diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 55 |
1 files changed, 29 insertions, 26 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index e691e8cfc5b..8548dcf5426 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.14 1997/12/21 05:18:18 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.15 1998/02/26 04:32:27 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -53,7 +53,7 @@ static List *find_join_paths(Query *root, List *outer_rels, int levels_needed); * * 'rels' is the list of single relation entries appearing in the query */ -List * +List * find_paths(Query *root, List *rels) { int levels_needed; @@ -189,66 +189,69 @@ find_join_paths(Query *root, List *outer_rels, int levels_needed) * rest will be deprecated in case of GEQO * *******************************************/ - while (--levels_needed) - { + 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. + * 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 + * * 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 + * 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*/ + + /* #define OPTIMIZER_DEBUG */ #ifdef OPTIMIZER_DEBUG 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 + * 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 */ |