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