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Diffstat (limited to 'src/backend/optimizer/util/relnode.c')
-rw-r--r-- | src/backend/optimizer/util/relnode.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c new file mode 100644 index 00000000000..351fb182107 --- /dev/null +++ b/src/backend/optimizer/util/relnode.c @@ -0,0 +1,123 @@ +/*------------------------------------------------------------------------- + * + * relnode.c-- + * Relation manipulation routines + * + * Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.1.1.1 1996/07/09 06:21:39 scrappy Exp $ + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "nodes/relation.h" + +#include "optimizer/internal.h" +#include "optimizer/pathnode.h" /* where the decls go */ +#include "optimizer/plancat.h" + + + +/* + * get_base_rel-- + * Returns relation entry corresponding to 'relid', creating a new one if + * necessary. This is for base relations. + * + */ +Rel *get_base_rel(Query* root, int relid) +{ + List *relids; + Rel *rel; + + relids = lconsi(relid, NIL); + rel = rel_member(relids, root->base_relation_list_); + if (rel==NULL) { + rel = makeNode(Rel); + rel->relids = relids; + rel->indexed = false; + rel->pages = 0; + rel->tuples = 0; + rel->width = 0; + rel->targetlist = NIL; + rel->pathlist = NIL; + rel->unorderedpath = (Path *)NULL; + rel->cheapestpath = (Path *)NULL; + rel->pruneable = true; + rel->classlist = NULL; + rel->ordering = NULL; + rel->relam = InvalidOid; + rel->clauseinfo = NIL; + rel->joininfo = NIL; + rel->innerjoin = NIL; + rel->superrels = NIL; + + root->base_relation_list_ = lcons(rel, + root->base_relation_list_); + + /* + * ??? the old lispy C code (get_rel) do a listp(relid) here but + * that can never happen since we already established relid is not + * a list. -ay 10/94 + */ + if(relid < 0) { + /* + * If the relation is a materialized relation, assume + * constants for sizes. + */ + rel->pages = _TEMP_RELATION_PAGES_; + rel->tuples = _TEMP_RELATION_TUPLES_; + + } else { + bool hasindex; + int pages, tuples; + + /* + * Otherwise, retrieve relation characteristics from the + * system catalogs. + */ + relation_info(root, relid, &hasindex, &pages, &tuples); + rel->indexed = hasindex; + rel->pages = pages; + rel->tuples = tuples; + } + } + return rel; +} + +/* + * get_join_rel-- + * Returns relation entry corresponding to 'relid' (a list of relids), + * creating a new one if necessary. This is for join relations. + * + */ +Rel *get_join_rel(Query *root, List *relid) +{ + return rel_member(relid, root->join_relation_list_); +} + +/* + * rel-member-- + * Determines whether a relation of id 'relid' is contained within a list + * 'rels'. + * + * Returns the corresponding entry in 'rels' if it is there. + * + */ +Rel * +rel_member(List *relid, List *rels) +{ + List *temp = NIL; + List *temprelid = NIL; + + if (relid!=NIL && rels!=NIL) { + foreach(temp,rels) { + temprelid = ((Rel*)lfirst(temp))->relids; + if(same(temprelid, relid)) + return((Rel*)(lfirst(temp))); + } + } + return(NULL); +} |