mirror of
https://github.com/postgres/postgres.git
synced 2025-11-13 16:22:44 +03:00
Postgres95 1.01 Distribution - Virgin Sources
This commit is contained in:
Marc G. Fournier
391
src/backend/optimizer/plan/initsplan.c
Normal file
391
src/backend/optimizer/plan/initsplan.c
Normal file
@@ -0,0 +1,391 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* initsplan.c--
|
||||
* Target list, qualification, joininfo initialization routines
|
||||
*
|
||||
* Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.1.1.1 1996/07/09 06:21:37 scrappy Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
#include "postgres.h"
|
||||
|
||||
#include "nodes/pg_list.h"
|
||||
#include "nodes/plannodes.h"
|
||||
#include "nodes/parsenodes.h"
|
||||
#include "nodes/relation.h"
|
||||
#include "nodes/makefuncs.h"
|
||||
|
||||
#include "utils/lsyscache.h"
|
||||
#include "utils/palloc.h"
|
||||
|
||||
#include "optimizer/internal.h"
|
||||
#include "optimizer/planmain.h"
|
||||
#include "optimizer/joininfo.h"
|
||||
#include "optimizer/pathnode.h"
|
||||
#include "optimizer/tlist.h"
|
||||
#include "optimizer/var.h"
|
||||
#include "optimizer/clauses.h"
|
||||
#include "optimizer/cost.h"
|
||||
|
||||
extern int Quiet;
|
||||
|
||||
static void add_clause_to_rels(Query *root, List *clause);
|
||||
static void add_join_clause_info_to_rels(Query *root, CInfo *clauseinfo,
|
||||
List *join_relids);
|
||||
static void add_vars_to_rels(Query *root, List *vars, List *join_relids);
|
||||
|
||||
static MergeOrder *mergesortop(Expr *clause);
|
||||
static Oid hashjoinop(Expr *clause);
|
||||
|
||||
|
||||
/*****************************************************************************
|
||||
*
|
||||
* TARGET LISTS
|
||||
*
|
||||
*****************************************************************************/
|
||||
|
||||
/*
|
||||
* initialize_rel_nodes--
|
||||
* Creates rel nodes for every relation mentioned in the target list
|
||||
* 'tlist' (if a node hasn't already been created) and adds them to
|
||||
* *query-relation-list*. Creates targetlist entries for each member of
|
||||
* 'tlist' and adds them to the tlist field of the appropriate rel node.
|
||||
*
|
||||
* Returns nothing.
|
||||
*/
|
||||
void
|
||||
initialize_base_rels_list(Query *root, List *tlist)
|
||||
{
|
||||
List *tlist_vars = NIL;
|
||||
List *l = NIL;
|
||||
List *tvar = NIL;
|
||||
|
||||
foreach (l, tlist) {
|
||||
TargetEntry *entry = (TargetEntry *) lfirst(l);
|
||||
|
||||
tlist_vars = append(tlist_vars, pull_var_clause(entry->expr));
|
||||
}
|
||||
|
||||
/* now, the target list only contains Var nodes */
|
||||
foreach (tvar, tlist_vars) {
|
||||
Var *var;
|
||||
Index varno;
|
||||
Rel *result;
|
||||
|
||||
var = (Var*)lfirst(tvar);
|
||||
varno = var->varno;
|
||||
result = get_base_rel(root, varno);
|
||||
|
||||
add_tl_element(result, var);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* add_missing_variables_to_base_rels -
|
||||
* If we have range variable(s) in the FROM clause that does not appear
|
||||
* in the target list nor qualifications, we add it to the base relation
|
||||
* list. For instance, "select f.x from foo f, foo f2" is a join of f and
|
||||
* f2. Note that if we have "select foo.x from foo f", it also gets turned
|
||||
* into a join.
|
||||
*/
|
||||
void
|
||||
add_missing_vars_to_base_rels(Query *root, List *tlist)
|
||||
{
|
||||
List *l;
|
||||
int varno;
|
||||
|
||||
varno = 1;
|
||||
foreach (l, root->rtable) {
|
||||
RangeTblEntry *rte = (RangeTblEntry *)lfirst(l);
|
||||
List *relids;
|
||||
Rel *result;
|
||||
Var *var;
|
||||
|
||||
relids = lconsi(varno, NIL);
|
||||
if (rte->inFromCl &&
|
||||
!rel_member(relids, root->base_relation_list_)) {
|
||||
|
||||
var = makeVar(varno, -2 , 26, varno, -2);
|
||||
/* add it to base_relation_list_ */
|
||||
result = get_base_rel(root, varno);
|
||||
add_tl_element(result, var);
|
||||
}
|
||||
pfree(relids);
|
||||
varno++;
|
||||
}
|
||||
|
||||
return;
|
||||
}
|
||||
|
||||
/*****************************************************************************
|
||||
*
|
||||
* QUALIFICATIONS
|
||||
*
|
||||
*****************************************************************************/
|
||||
|
||||
|
||||
|
||||
/*
|
||||
* initialize-qualification--
|
||||
* Initializes ClauseInfo and JoinInfo fields of relation entries for all
|
||||
* relations appearing within clauses. Creates new relation entries if
|
||||
* necessary, adding them to *query-relation-list*.
|
||||
*
|
||||
* Returns nothing of interest.
|
||||
*/
|
||||
void
|
||||
initialize_base_rels_jinfo(Query *root, List *clauses)
|
||||
{
|
||||
List *clause;
|
||||
|
||||
foreach (clause, clauses) {
|
||||
add_clause_to_rels(root, lfirst(clause));
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* add-clause-to-rels--
|
||||
* Add clause information to either the 'ClauseInfo' or 'JoinInfo' field
|
||||
* of a relation entry(depending on whether or not the clause is a join)
|
||||
* by creating a new ClauseInfo node and setting appropriate fields
|
||||
* within the nodes.
|
||||
*
|
||||
* Returns nothing of interest.
|
||||
*/
|
||||
static void
|
||||
add_clause_to_rels(Query *root, List *clause)
|
||||
{
|
||||
List *relids;
|
||||
List *vars;
|
||||
CInfo *clauseinfo = makeNode(CInfo);
|
||||
|
||||
/*
|
||||
* Retrieve all relids and vars contained within the clause.
|
||||
*/
|
||||
clause_relids_vars((Node*)clause, &relids, &vars);
|
||||
|
||||
|
||||
clauseinfo->clause = (Expr*)clause;
|
||||
clauseinfo->notclause = contains_not((Node*)clause);
|
||||
clauseinfo->selectivity = 0;
|
||||
clauseinfo->indexids = NIL;
|
||||
clauseinfo->mergesortorder = (MergeOrder*)NULL;
|
||||
clauseinfo->hashjoinoperator = (Oid)0;
|
||||
|
||||
|
||||
|
||||
if(length(relids) == 1) {
|
||||
Rel *rel = get_base_rel(root, lfirsti(relids));
|
||||
|
||||
/*
|
||||
* There is only one relation participating in 'clause',
|
||||
* so 'clause' must be a restriction clause.
|
||||
*/
|
||||
|
||||
/* the selectivity of the clause must be computed
|
||||
regardless of whether it's a restriction or a join clause */
|
||||
if (is_funcclause((Node*)clause))
|
||||
{
|
||||
/*
|
||||
* XXX If we have a func clause set selectivity to 1/3,
|
||||
* really need a true selectivity function.
|
||||
*/
|
||||
clauseinfo->selectivity = (Cost)0.3333333;
|
||||
}
|
||||
else
|
||||
{
|
||||
clauseinfo->selectivity =
|
||||
compute_clause_selec(root, (Node*)clause,
|
||||
NIL);
|
||||
}
|
||||
rel->clauseinfo = lcons(clauseinfo,
|
||||
rel->clauseinfo);
|
||||
} else {
|
||||
/*
|
||||
* 'clause' is a join clause, since there is more than one
|
||||
* atom in the relid list.
|
||||
*/
|
||||
|
||||
if (is_funcclause((Node*)clause))
|
||||
{
|
||||
/*
|
||||
* XXX If we have a func clause set selectivity to 1/3,
|
||||
* really need a true selectivity function.
|
||||
*/
|
||||
clauseinfo->selectivity = (Cost)0.3333333;
|
||||
}
|
||||
else
|
||||
{
|
||||
clauseinfo->selectivity =
|
||||
compute_clause_selec(root, (Node*)clause,
|
||||
NIL);
|
||||
}
|
||||
add_join_clause_info_to_rels(root, clauseinfo, relids);
|
||||
add_vars_to_rels(root,vars, relids);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* add-join-clause-info-to-rels--
|
||||
* For every relation participating in a join clause, add 'clauseinfo' to
|
||||
* the appropriate joininfo node(creating a new one and adding it to the
|
||||
* appropriate rel node if necessary).
|
||||
*
|
||||
* 'clauseinfo' describes the join clause
|
||||
* 'join-relids' is the list of relations participating in the join clause
|
||||
*
|
||||
* Returns nothing.
|
||||
*
|
||||
*/
|
||||
static void
|
||||
add_join_clause_info_to_rels(Query *root, CInfo *clauseinfo, List *join_relids)
|
||||
{
|
||||
List *join_relid;
|
||||
|
||||
foreach (join_relid, join_relids) {
|
||||
JInfo *joininfo =
|
||||
find_joininfo_node(get_base_rel(root, lfirsti(join_relid)),
|
||||
intLispRemove((int)lfirst(join_relid),
|
||||
join_relids));
|
||||
joininfo->jinfoclauseinfo =
|
||||
lcons(clauseinfo, joininfo->jinfoclauseinfo);
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* add-vars-to-rels--
|
||||
* For each variable appearing in a clause,
|
||||
* (1) If a targetlist entry for the variable is not already present in
|
||||
* the appropriate relation's target list, add one.
|
||||
* (2) If a targetlist entry is already present, but the var is part of a
|
||||
* join clause, add the relids of the join relations to the JoinList
|
||||
* entry of the targetlist entry.
|
||||
*
|
||||
* 'vars' is the list of var nodes
|
||||
* 'join-relids' is the list of relids appearing in the join clause
|
||||
* (if this is a join clause)
|
||||
*
|
||||
* Returns nothing.
|
||||
*/
|
||||
static void
|
||||
add_vars_to_rels(Query *root, List *vars, List *join_relids)
|
||||
{
|
||||
Var *var;
|
||||
List *temp = NIL;
|
||||
Rel *rel = (Rel*)NULL;
|
||||
TargetEntry *tlistentry;
|
||||
|
||||
foreach (temp, vars) {
|
||||
var = (Var*)lfirst(temp);
|
||||
rel = get_base_rel(root, var->varno);
|
||||
tlistentry = tlistentry_member(var, rel->targetlist);
|
||||
if(tlistentry==NULL)
|
||||
/* add a new entry */
|
||||
add_tl_element(rel, var);
|
||||
}
|
||||
}
|
||||
|
||||
/*****************************************************************************
|
||||
*
|
||||
* JOININFO
|
||||
*
|
||||
*****************************************************************************/
|
||||
|
||||
/*
|
||||
* initialize-join-clause-info--
|
||||
* Set the MergeSortable or HashJoinable field for every joininfo node
|
||||
* (within a rel node) and the MergeSortOrder or HashJoinOp field for
|
||||
* each clauseinfo node(within a joininfo node) for all relations in a
|
||||
* query.
|
||||
*
|
||||
* Returns nothing.
|
||||
*/
|
||||
void
|
||||
initialize_join_clause_info(List *rel_list)
|
||||
{
|
||||
List *x, *y, *z;
|
||||
Rel *rel;
|
||||
JInfo *joininfo;
|
||||
CInfo *clauseinfo;
|
||||
Expr *clause;
|
||||
|
||||
foreach (x, rel_list) {
|
||||
rel = (Rel*)lfirst(x);
|
||||
foreach (y, rel->joininfo) {
|
||||
joininfo = (JInfo*)lfirst(y);
|
||||
foreach (z, joininfo->jinfoclauseinfo) {
|
||||
clauseinfo = (CInfo*)lfirst(z);
|
||||
clause = clauseinfo->clause;
|
||||
if(join_clause_p((Node*)clause)) {
|
||||
MergeOrder *sortop = (MergeOrder*)NULL;
|
||||
Oid hashop = (Oid)NULL;
|
||||
|
||||
if (_enable_mergesort_)
|
||||
sortop = mergesortop(clause);
|
||||
if (_enable_hashjoin_)
|
||||
hashop = hashjoinop(clause);
|
||||
|
||||
if (sortop) {
|
||||
clauseinfo->mergesortorder = sortop;
|
||||
joininfo->mergesortable = true;
|
||||
}
|
||||
if (hashop) {
|
||||
clauseinfo->hashjoinoperator = hashop;
|
||||
joininfo->hashjoinable = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* mergesortop--
|
||||
* Returns the mergesort operator of an operator iff 'clause' is
|
||||
* mergesortable, i.e., both operands are single vars and the operator is
|
||||
* a mergesortable operator.
|
||||
*/
|
||||
static MergeOrder *
|
||||
mergesortop(Expr *clause)
|
||||
{
|
||||
Oid leftOp, rightOp;
|
||||
bool sortable;
|
||||
|
||||
sortable = op_mergesortable(((Oper*)clause->oper)->opno,
|
||||
(get_leftop(clause))->vartype,
|
||||
(get_rightop(clause))->vartype,
|
||||
&leftOp,
|
||||
&rightOp);
|
||||
|
||||
if (sortable) {
|
||||
MergeOrder *morder = makeNode(MergeOrder);
|
||||
|
||||
morder->join_operator = ((Oper*)clause->oper)->opno;
|
||||
morder->left_operator = leftOp;
|
||||
morder->right_operator = rightOp;
|
||||
morder->left_type = (get_leftop(clause))->vartype;
|
||||
morder->right_type = (get_rightop(clause))->vartype;
|
||||
return (morder);
|
||||
} else
|
||||
return(NULL);
|
||||
}
|
||||
|
||||
/*
|
||||
* hashjoinop--
|
||||
* Returns the hashjoin operator of an operator iff 'clause' is
|
||||
* hashjoinable, i.e., both operands are single vars and the operator is
|
||||
* a hashjoinable operator.
|
||||
*/
|
||||
static Oid
|
||||
hashjoinop(Expr *clause)
|
||||
{
|
||||
return(op_hashjoinable(((Oper*)clause->oper)->opno,
|
||||
(get_leftop(clause))->vartype,
|
||||
(get_rightop(clause))->vartype));
|
||||
}
|
||||
Reference in New Issue
Block a user