diff options
Diffstat (limited to 'src/backend/optimizer/geqo/geqo_paths.c')
| -rw-r--r-- | src/backend/optimizer/geqo/geqo_paths.c | 190 |
1 files changed, 99 insertions, 91 deletions
diff --git a/src/backend/optimizer/geqo/geqo_paths.c b/src/backend/optimizer/geqo/geqo_paths.c index a22be406f5a..d98855d2887 100644 --- a/src/backend/optimizer/geqo/geqo_paths.c +++ b/src/backend/optimizer/geqo/geqo_paths.c @@ -1,11 +1,11 @@ /*------------------------------------------------------------------------- * * geqo_paths.c-- - * Routines to process redundant paths and relations + * Routines to process redundant paths and relations * * Copyright (c) 1994, Regents of the University of California * - * $Id: geqo_paths.c,v 1.4 1997/06/11 02:44:12 vadim Exp $ + * $Id: geqo_paths.c,v 1.5 1997/09/07 04:43:17 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -28,120 +28,128 @@ #include "optimizer/geqo_paths.h" -static List *geqo_prune_rel(Rel *rel, List *other_rels); -static Path *set_paths(Rel *rel, Path *unorderedpath); +static List *geqo_prune_rel(Rel * rel, List * other_rels); +static Path *set_paths(Rel * rel, Path * unorderedpath); -/* +/* * geqo-prune-rels-- - * Removes any redundant relation entries from a list of rel nodes - * 'rel-list'. - * - * Returns the resulting list. - * + * Removes any redundant relation entries from a list of rel nodes + * 'rel-list'. + * + * Returns the resulting list. + * */ -List *geqo_prune_rels(List *rel_list) +List * +geqo_prune_rels(List * rel_list) { - List *temp_list = NIL; - - if (rel_list != NIL) { - temp_list = lcons(lfirst(rel_list), - geqo_prune_rels(geqo_prune_rel((Rel*)lfirst(rel_list), - lnext(rel_list)))); - } - return(temp_list); + List *temp_list = NIL; + + if (rel_list != NIL) + { + temp_list = lcons(lfirst(rel_list), + geqo_prune_rels(geqo_prune_rel((Rel *) lfirst(rel_list), + lnext(rel_list)))); + } + return (temp_list); } -/* +/* * geqo-prune-rel-- - * Prunes those relations from 'other-rels' that are redundant with - * 'rel'. A relation is redundant if it is built up of the same - * relations as 'rel'. Paths for the redundant relation are merged into - * the pathlist of 'rel'. - * + * Prunes those relations from 'other-rels' that are redundant with + * 'rel'. A relation is redundant if it is built up of the same + * relations as 'rel'. Paths for the redundant relation are merged into + * the pathlist of 'rel'. + * * Returns a list of non-redundant relations, and sets the pathlist field * of 'rel' appropriately. - * + * */ -static List * -geqo_prune_rel(Rel *rel, List *other_rels) +static List * +geqo_prune_rel(Rel * rel, List * other_rels) { - List *i = NIL; - List *t_list = NIL; - List *temp_node = NIL; - Rel *other_rel = (Rel *)NULL; - - foreach(i, other_rels) { - other_rel = (Rel*)lfirst(i); - if(same(rel->relids, other_rel->relids)) { - 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); - } - } - return(t_list); + List *i = NIL; + List *t_list = NIL; + List *temp_node = NIL; + Rel *other_rel = (Rel *) NULL; + + foreach(i, other_rels) + { + other_rel = (Rel *) lfirst(i); + if (same(rel->relids, other_rel->relids)) + { + 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); + } + } + return (t_list); } -/* +/* * geqo-rel-paths-- - * For a relation 'rel' (which corresponds to a join - * relation), set pointers to the unordered path and cheapest paths - * (if the unordered path isn't the cheapest, it is pruned), and - * reset the relation's size field to reflect the join. - * + * For a relation 'rel' (which corresponds to a join + * relation), set pointers to the unordered path and cheapest paths + * (if the unordered path isn't the cheapest, it is pruned), and + * reset the relation's size field to reflect the join. + * * Returns nothing of interest. - * + * */ void -geqo_rel_paths(Rel *rel) +geqo_rel_paths(Rel * rel) { - List *y = NIL; - Path *path = (Path*)NULL; - JoinPath *cheapest = (JoinPath*)NULL; - - rel->size = 0; - foreach(y, rel->pathlist) - { - path = (Path*)lfirst(y); - - if(!path->p_ordering.ord.sortop) + List *y = NIL; + Path *path = (Path *) NULL; + JoinPath *cheapest = (JoinPath *) NULL; + + rel->size = 0; + foreach(y, rel->pathlist) + { + path = (Path *) lfirst(y); + + if (!path->p_ordering.ord.sortop) break; - } + } - cheapest = (JoinPath*)set_paths(rel, path); - if ( IsA_JoinPath (cheapest) ) - rel->size = compute_joinrel_size(cheapest); + cheapest = (JoinPath *) set_paths(rel, path); + if (IsA_JoinPath(cheapest)) + rel->size = compute_joinrel_size(cheapest); } -/* +/* * set-path-- - * Compares the unordered path for a relation with the cheapest path. If - * the unordered path is not cheapest, it is pruned. - * - * Resets the pointers in 'rel' for unordered and cheapest paths. - * + * Compares the unordered path for a relation with the cheapest path. If + * the unordered path is not cheapest, it is pruned. + * + * Resets the pointers in 'rel' for unordered and cheapest paths. + * * Returns the cheapest path. - * + * */ -static Path * -set_paths(Rel *rel, Path *unorderedpath) +static Path * +set_paths(Rel * rel, Path * unorderedpath) { - Path *cheapest = set_cheapest(rel, rel->pathlist); - - /* don't prune if not pruneable -- JMH, 11/23/92 */ - if(unorderedpath != cheapest - && rel->pruneable) { - - rel->unorderedpath = (Path *)NULL; - rel->pathlist = lremove(unorderedpath, rel->pathlist); - } else { - rel->unorderedpath = (Path *)unorderedpath; - } - - return(cheapest); + Path *cheapest = set_cheapest(rel, rel->pathlist); + + /* don't prune if not pruneable -- JMH, 11/23/92 */ + if (unorderedpath != cheapest + && rel->pruneable) + { + + rel->unorderedpath = (Path *) NULL; + rel->pathlist = lremove(unorderedpath, rel->pathlist); + } + else + { + rel->unorderedpath = (Path *) unorderedpath; + } + + return (cheapest); } - |