*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.49 2003/05/28 22:32:49 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.50 2003/06/15 22:51:45 tgl Exp $
*
* NOTES
* XXX a few of the following functions are duplicated to handle
}
/*
+ * llastnode
+ *
+ * Get the last node of l ... NIL if empty list
+ */
+List *
+llastnode(List *l)
+{
+ if (l == NIL)
+ return NIL;
+ while (lnext(l) != NIL)
+ l = lnext(l);
+ return l;
+}
+
+/*
* freeList
*
* Free the List nodes of a list
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.207 2003/06/06 15:04:02 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.208 2003/06/15 22:51:45 tgl Exp $
*
* NOTES
* Every node type that can appear in stored rules' parsetrees *must*
WRITE_NODE_FIELD(indexinfo);
WRITE_NODE_FIELD(indexqual);
+ WRITE_NODE_FIELD(indexjoinclauses);
WRITE_ENUM_FIELD(indexscandir, ScanDirection);
WRITE_FLOAT_FIELD(rows, "%.2f");
}
{
WRITE_NODE_TYPE("RESTRICTINFO");
+ /* NB: this isn't a complete set of fields */
WRITE_NODE_FIELD(clause);
WRITE_BOOL_FIELD(ispusheddown);
WRITE_NODE_FIELD(subclauseindices);
WRITE_OID_FIELD(mergejoinoperator);
WRITE_OID_FIELD(left_sortop);
WRITE_OID_FIELD(right_sortop);
+ WRITE_NODE_FIELD(left_pathkey);
+ WRITE_NODE_FIELD(right_pathkey);
WRITE_OID_FIELD(hashjoinoperator);
}
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.143 2003/05/28 22:32:49 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.144 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
IndexOptInfo *index,
Expr *clause);
static List *group_clauses_by_indexkey(RelOptInfo *rel, IndexOptInfo *index);
-static List *group_clauses_by_indexkey_for_join(RelOptInfo *rel,
- IndexOptInfo *index,
- Relids outer_relids,
- bool isouterjoin);
+static List *group_clauses_by_indexkey_for_join(Query *root,
+ RelOptInfo *rel, IndexOptInfo *index,
+ Relids outer_relids,
+ JoinType jointype, bool isouterjoin);
static bool match_clause_to_indexcol(RelOptInfo *rel, IndexOptInfo *index,
int indexcol, Oid opclass, Expr *clause);
static bool match_join_clause_to_indexcol(RelOptInfo *rel, IndexOptInfo *index,
* will already have been generated for it.)
*/
static List *
-group_clauses_by_indexkey_for_join(RelOptInfo *rel, IndexOptInfo *index,
- Relids outer_relids, bool isouterjoin)
+group_clauses_by_indexkey_for_join(Query *root,
+ RelOptInfo *rel, IndexOptInfo *index,
+ Relids outer_relids,
+ JoinType jointype, bool isouterjoin)
{
FastList clausegroup_list;
bool jfound = false;
}
}
+ /*
+ * If we found join clauses in more than one joininfo list, we may
+ * now have clauses that are known redundant. Get rid of 'em.
+ * (There is no point in looking at restriction clauses, because
+ * remove_redundant_join_clauses will never think they are
+ * redundant, so we do this before adding restriction clauses to
+ * the clause group.)
+ */
+ if (FastListValue(&clausegroup) != NIL)
+ {
+ List *nl;
+
+ nl = remove_redundant_join_clauses(root,
+ FastListValue(&clausegroup),
+ jointype);
+ FastListFromList(&clausegroup, nl);
+ }
+
/* We can also use plain restriction clauses for the rel */
foreach(i, rel->baserestrictinfo)
{
List *clausegroups;
/* find useful clauses for this index and outerjoin set */
- clausegroups = group_clauses_by_indexkey_for_join(rel,
+ clausegroups = group_clauses_by_indexkey_for_join(root,
+ rel,
index,
index_outer_relids,
+ jointype,
isouterjoin);
if (clausegroups)
{
*allclauses,
*l;
- /* XXX this code ought to be merged with create_index_path? */
+ /* XXX perhaps this code should be merged with create_index_path? */
pathnode->path.pathtype = T_IndexScan;
pathnode->path.parent = rel;
indexquals = expand_indexqual_conditions(index, clausegroups);
/*
+ * Also make a flattened list of the RestrictInfo nodes; createplan.c
+ * will need this later. We assume here that we can destructively
+ * modify the passed-in clausegroups list structure.
+ */
+ allclauses = NIL;
+ foreach(l, clausegroups)
+ {
+ /* nconc okay here since same clause couldn't be in two sublists */
+ allclauses = nconc(allclauses, (List *) lfirst(l));
+ }
+
+ /*
* Note that we are making a pathnode for a single-scan indexscan;
- * therefore, both indexinfo and indexqual should be single-element lists.
+ * therefore, indexinfo and indexqual should be single-element lists.
*/
pathnode->indexinfo = makeList1(index);
pathnode->indexqual = makeList1(indexquals);
+ pathnode->indexjoinclauses = makeList1(allclauses);
/* We don't actually care what order the index scans in ... */
pathnode->indexscandir = NoMovementScanDirection;
* linking them into different lists, it should be sufficient to use
* pointer comparison to remove duplicates.)
*
- * We assume we can destructively modify the input sublists.
- *
* Always assume the join type is JOIN_INNER; even if some of the
* join clauses come from other contexts, that's not our problem.
*/
- allclauses = NIL;
- foreach(l, clausegroups)
- {
- /* nconc okay here since same clause couldn't be in two sublists */
- allclauses = nconc(allclauses, (List *) lfirst(l));
- }
allclauses = set_ptrUnion(rel->baserestrictinfo, allclauses);
pathnode->rows = rel->tuples *
restrictlist_selectivity(root,
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/orindxpath.c,v 1.50 2003/05/28 22:32:49 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/orindxpath.c,v 1.51 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
*/
pathnode->path.pathkeys = NIL;
+ /* It's not an innerjoin path. */
+ pathnode->indexjoinclauses = NIL;
+
/* We don't actually care what order the index scans in. */
pathnode->indexscandir = NoMovementScanDirection;
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.144 2003/05/28 23:06:16 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.145 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
List *tlist, List *scan_clauses);
static FunctionScan *create_functionscan_plan(Path *best_path,
List *tlist, List *scan_clauses);
-static NestLoop *create_nestloop_plan(Query *root,
- NestPath *best_path, List *tlist,
- List *joinclauses, List *otherclauses,
+static NestLoop *create_nestloop_plan(Query *root, NestPath *best_path,
Plan *outer_plan, Plan *inner_plan);
-static MergeJoin *create_mergejoin_plan(Query *root,
- MergePath *best_path, List *tlist,
- List *joinclauses, List *otherclauses,
+static MergeJoin *create_mergejoin_plan(Query *root, MergePath *best_path,
Plan *outer_plan, Plan *inner_plan);
-static HashJoin *create_hashjoin_plan(Query *root,
- HashPath *best_path, List *tlist,
- List *joinclauses, List *otherclauses,
+static HashJoin *create_hashjoin_plan(Query *root, HashPath *best_path,
Plan *outer_plan, Plan *inner_plan);
static void fix_indxqual_references(List *indexquals, IndexPath *index_path,
List **fixed_indexquals,
static Join *
create_join_plan(Query *root, JoinPath *best_path)
{
- List *join_tlist = best_path->path.parent->targetlist;
Plan *outer_plan;
Plan *inner_plan;
- List *joinclauses;
- List *otherclauses;
Join *plan;
outer_plan = create_plan(root, best_path->outerjoinpath);
inner_plan = create_plan(root, best_path->innerjoinpath);
- if (IS_OUTER_JOIN(best_path->jointype))
- {
- get_actual_join_clauses(best_path->joinrestrictinfo,
- &joinclauses, &otherclauses);
- }
- else
- {
- /* We can treat all clauses alike for an inner join */
- joinclauses = get_actual_clauses(best_path->joinrestrictinfo);
- otherclauses = NIL;
- }
-
switch (best_path->path.pathtype)
{
case T_MergeJoin:
plan = (Join *) create_mergejoin_plan(root,
(MergePath *) best_path,
- join_tlist,
- joinclauses,
- otherclauses,
outer_plan,
inner_plan);
break;
case T_HashJoin:
plan = (Join *) create_hashjoin_plan(root,
(HashPath *) best_path,
- join_tlist,
- joinclauses,
- otherclauses,
outer_plan,
inner_plan);
break;
case T_NestLoop:
plan = (Join *) create_nestloop_plan(root,
(NestPath *) best_path,
- join_tlist,
- joinclauses,
- otherclauses,
outer_plan,
inner_plan);
break;
default:
- elog(ERROR, "create_join_plan: unknown node type: %d",
+ elog(ERROR, "unsupported node type %d",
best_path->path.pathtype);
plan = NULL; /* keep compiler quiet */
break;
static NestLoop *
create_nestloop_plan(Query *root,
NestPath *best_path,
- List *tlist,
- List *joinclauses,
- List *otherclauses,
Plan *outer_plan,
Plan *inner_plan)
{
+ List *tlist = best_path->path.parent->targetlist;
+ List *joinrestrictclauses = best_path->joinrestrictinfo;
+ List *joinclauses;
+ List *otherclauses;
NestLoop *join_plan;
- if (IsA(inner_plan, IndexScan))
+ if (IsA(best_path->innerjoinpath, IndexPath))
{
/*
* An index is being used to reduce the number of tuples scanned
* (otherwise, several different sets of clauses are being ORed
* together).
*
- * Note we must compare against indxqualorig not the "fixed" indxqual
- * (which has index attnos instead of relation attnos, and may have
- * been commuted as well).
+ * We can also remove any join clauses that are redundant with those
+ * being used in the index scan; prior redundancy checks will not
+ * have caught this case because the join clauses would never have
+ * been put in the same joininfo list.
+ *
+ * This would be a waste of time if the indexpath was an ordinary
+ * indexpath and not a special innerjoin path. We will skip it in
+ * that case since indexjoinclauses is NIL in an ordinary indexpath.
*/
- IndexScan *innerscan = (IndexScan *) inner_plan;
- List *indxqualorig = innerscan->indxqualorig;
+ IndexPath *innerpath = (IndexPath *) best_path->innerjoinpath;
+ List *indexjoinclauses = innerpath->indexjoinclauses;
- if (length(indxqualorig) == 1) /* single indexscan? */
+ if (length(indexjoinclauses) == 1) /* single indexscan? */
{
- /* No work needed if indxqual refers only to its own relation... */
- if (NumRelids((Node *) indxqualorig) > 1)
- joinclauses = set_difference(joinclauses,
- lfirst(indxqualorig));
+ joinrestrictclauses =
+ select_nonredundant_join_clauses(root,
+ joinrestrictclauses,
+ lfirst(indexjoinclauses),
+ best_path->jointype);
}
}
+ /* Get the join qual clauses (in plain expression form) */
+ if (IS_OUTER_JOIN(best_path->jointype))
+ {
+ get_actual_join_clauses(joinrestrictclauses,
+ &joinclauses, &otherclauses);
+ }
+ else
+ {
+ /* We can treat all clauses alike for an inner join */
+ joinclauses = get_actual_clauses(joinrestrictclauses);
+ otherclauses = NIL;
+ }
+
join_plan = make_nestloop(tlist,
joinclauses,
otherclauses,
static MergeJoin *
create_mergejoin_plan(Query *root,
MergePath *best_path,
- List *tlist,
- List *joinclauses,
- List *otherclauses,
Plan *outer_plan,
Plan *inner_plan)
{
+ List *tlist = best_path->jpath.path.parent->targetlist;
+ List *joinclauses;
+ List *otherclauses;
List *mergeclauses;
MergeJoin *join_plan;
+ /* Get the join qual clauses (in plain expression form) */
+ if (IS_OUTER_JOIN(best_path->jpath.jointype))
+ {
+ get_actual_join_clauses(best_path->jpath.joinrestrictinfo,
+ &joinclauses, &otherclauses);
+ }
+ else
+ {
+ /* We can treat all clauses alike for an inner join */
+ joinclauses = get_actual_clauses(best_path->jpath.joinrestrictinfo);
+ otherclauses = NIL;
+ }
+
/*
* Remove the mergeclauses from the list of join qual clauses, leaving
* the list of quals that must be checked as qpquals.
static HashJoin *
create_hashjoin_plan(Query *root,
HashPath *best_path,
- List *tlist,
- List *joinclauses,
- List *otherclauses,
Plan *outer_plan,
Plan *inner_plan)
{
+ List *tlist = best_path->jpath.path.parent->targetlist;
+ List *joinclauses;
+ List *otherclauses;
List *hashclauses;
HashJoin *join_plan;
Hash *hash_plan;
List *innerhashkeys;
List *hcl;
+ /* Get the join qual clauses (in plain expression form) */
+ if (IS_OUTER_JOIN(best_path->jpath.jointype))
+ {
+ get_actual_join_clauses(best_path->jpath.joinrestrictinfo,
+ &joinclauses, &otherclauses);
+ }
+ else
+ {
+ /* We can treat all clauses alike for an inner join */
+ joinclauses = get_actual_clauses(best_path->jpath.joinrestrictinfo);
+ otherclauses = NIL;
+ }
+
/*
* Remove the hashclauses from the list of join qual clauses, leaving
* the list of quals that must be checked as qpquals.
* Adjust indexqual clauses to the form the executor's indexqual
* machinery needs, and check for recheckable (lossy) index conditions.
*
- * We have four tasks here:
+ * We have three tasks here:
* * Index keys must be represented by Var nodes with varattno set to the
* index's attribute number, not the attribute number in the original rel.
- * * indxpath.c may have selected an index that is binary-compatible with
- * the actual expression operator, but not exactly the same datatype.
- * We must replace the expression's operator with the binary-compatible
- * equivalent operator that the index will recognize.
* * If the index key is on the right, commute the clause to put it on the
* left. (Someday the executor might not need this, but for now it does.)
* * If the indexable operator is marked 'amopreqcheck' in pg_amop, then
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.89 2003/05/26 00:11:27 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.90 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
pathnode->indexinfo = makeList1(index);
pathnode->indexqual = makeList1(indexquals);
+ /* It's not an innerjoin path. */
+ pathnode->indexjoinclauses = NIL;
+
pathnode->indexscandir = indexscandir;
/*
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.16 2003/01/24 03:58:43 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.17 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "optimizer/var.h"
+static bool join_clause_is_redundant(Query *root,
+ RestrictInfo *rinfo,
+ List *reference_list,
+ JoinType jointype);
+
+
/*
* restriction_is_or_clause
*
* discussion). We detect that case and omit the redundant clause from the
* result list.
*
+ * The result is a fresh List, but it points to the same member nodes
+ * as were in the input.
+ */
+List *
+remove_redundant_join_clauses(Query *root, List *restrictinfo_list,
+ JoinType jointype)
+{
+ List *result = NIL;
+ List *item;
+
+ foreach(item, restrictinfo_list)
+ {
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(item);
+
+ /* drop it if redundant with any prior clause */
+ if (join_clause_is_redundant(root, rinfo, result, jointype))
+ continue;
+
+ /* otherwise, add it to result list */
+ result = lappend(result, rinfo);
+ }
+
+ return result;
+}
+
+/*
+ * select_nonredundant_join_clauses
+ *
+ * Given a list of RestrictInfo clauses that are to be applied in a join,
+ * select the ones that are not redundant with any clause in the
+ * reference_list.
+ *
+ * This is similar to remove_redundant_join_clauses, but we are looking for
+ * redundancies with a separate list of clauses (i.e., clauses that have
+ * already been applied below the join itself).
+ *
+ * Note that we assume the given restrictinfo_list has already been checked
+ * for local redundancies, so we don't check again.
+ */
+List *
+select_nonredundant_join_clauses(Query *root,
+ List *restrictinfo_list,
+ List *reference_list,
+ JoinType jointype)
+{
+ List *result = NIL;
+ List *item;
+
+ foreach(item, restrictinfo_list)
+ {
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(item);
+
+ /* drop it if redundant with any reference clause */
+ if (join_clause_is_redundant(root, rinfo, reference_list, jointype))
+ continue;
+
+ /* otherwise, add it to result list */
+ result = lappend(result, rinfo);
+ }
+
+ return result;
+}
+
+/*
+ * join_clause_is_redundant
+ * Returns true if rinfo is redundant with any clause in reference_list.
+ *
+ * This is the guts of both remove_redundant_join_clauses and
+ * select_nonredundant_join_clauses. See the docs above for motivation.
+ *
* We can detect redundant mergejoinable clauses very cheaply by using their
* left and right pathkeys, which uniquely identify the sets of equijoined
* variables in question. All the members of a pathkey set that are in the
* except one is pushed down into an outer join and the other isn't,
* then they're not really redundant, because one constrains the
* joined rows after addition of null fill rows, and the other doesn't.
- *
- * The result is a fresh List, but it points to the same member nodes
- * as were in the input.
*/
-List *
-remove_redundant_join_clauses(Query *root, List *restrictinfo_list,
- JoinType jointype)
+static bool
+join_clause_is_redundant(Query *root,
+ RestrictInfo *rinfo,
+ List *reference_list,
+ JoinType jointype)
{
- List *result = NIL;
- List *item;
+ /* always consider exact duplicates redundant */
+ /* XXX would it be sufficient to use ptrMember here? */
+ if (member(rinfo, reference_list))
+ return true;
- foreach(item, restrictinfo_list)
+ /* check for redundant merge clauses */
+ if (rinfo->mergejoinoperator != InvalidOid)
{
- RestrictInfo *rinfo = (RestrictInfo *) lfirst(item);
+ bool redundant = false;
+ List *refitem;
- /* always eliminate duplicates */
- if (member(rinfo, result))
- continue;
+ cache_mergeclause_pathkeys(root, rinfo);
- /* check for redundant merge clauses */
- if (rinfo->mergejoinoperator != InvalidOid)
+ /* do the cheap tests first */
+ foreach(refitem, reference_list)
{
- bool redundant = false;
- List *olditem;
+ RestrictInfo *refrinfo = (RestrictInfo *) lfirst(refitem);
- cache_mergeclause_pathkeys(root, rinfo);
-
- /* do the cheap tests first */
- foreach(olditem, result)
+ if (refrinfo->mergejoinoperator != InvalidOid &&
+ rinfo->left_pathkey == refrinfo->left_pathkey &&
+ rinfo->right_pathkey == refrinfo->right_pathkey &&
+ (rinfo->ispusheddown == refrinfo->ispusheddown ||
+ !IS_OUTER_JOIN(jointype)))
{
- RestrictInfo *oldrinfo = (RestrictInfo *) lfirst(olditem);
-
- if (oldrinfo->mergejoinoperator != InvalidOid &&
- rinfo->left_pathkey == oldrinfo->left_pathkey &&
- rinfo->right_pathkey == oldrinfo->right_pathkey &&
- (rinfo->ispusheddown == oldrinfo->ispusheddown ||
- !IS_OUTER_JOIN(jointype)))
- {
- redundant = true;
- break;
- }
- }
-
- if (redundant)
- {
- /*
- * It looks redundant, now check for "var = const" case.
- * If left_relids/right_relids are set, then there are
- * definitely vars on both sides; else we must check the
- * hard way.
- */
- if (rinfo->left_relids)
- continue; /* var = var, so redundant */
- if (contain_var_clause(get_leftop(rinfo->clause)) &&
- contain_var_clause(get_rightop(rinfo->clause)))
- continue; /* var = var, so redundant */
- /* else var = const, not redundant */
+ redundant = true;
+ break;
}
}
- /* otherwise, add it to result list */
- result = lappend(result, rinfo);
+ if (redundant)
+ {
+ /*
+ * It looks redundant, now check for "var = const" case.
+ * If left_relids/right_relids are set, then there are
+ * definitely vars on both sides; else we must check the
+ * hard way.
+ */
+ if (rinfo->left_relids)
+ return true; /* var = var, so redundant */
+ if (contain_var_clause(get_leftop(rinfo->clause)) &&
+ contain_var_clause(get_rightop(rinfo->clause)))
+ return true; /* var = var, so redundant */
+ /* else var = const, not redundant */
+ }
}
- return result;
+ /* otherwise, not redundant */
+ return false;
}
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: pg_list.h,v 1.36 2003/05/28 22:32:50 tgl Exp $
+ * $Id: pg_list.h,v 1.37 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
} FastList;
#define FastListInit(fl) ( (fl)->head = (fl)->tail = NIL )
+#define FastListFromList(fl, l) \
+ ( (fl)->head = (l), (fl)->tail = llastnode((fl)->head) )
#define FastListValue(fl) ( (fl)->head )
extern void *nth(int n, List *l);
extern int length(List *list);
extern void *llast(List *list);
+extern List *llastnode(List *list);
extern bool member(void *datum, List *list);
extern bool ptrMember(void *datum, List *list);
extern bool intMember(int datum, List *list);
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: relation.h,v 1.80 2003/05/28 16:04:02 tgl Exp $
+ * $Id: relation.h,v 1.81 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* Also note that indexquals lists do not contain RestrictInfo nodes,
* just bare clause expressions.
*
+ * 'indexjoinclauses' is NIL for an ordinary indexpath (one that does not
+ * use any join clauses in the index conditions). For an innerjoin indexpath,
+ * it has the same structure as 'indexqual', but references the RestrictInfo
+ * nodes from which the indexqual was built, rather than the bare clause
+ * expressions. (Note: there isn't necessarily a one-to-one correspondence
+ * between RestrictInfos and expressions, because of expansion of special
+ * indexable operators.) We need this so that we can eliminate redundant
+ * join clauses when plans are built.
+ *
* 'indexscandir' is one of:
* ForwardScanDirection: forward scan of an ordered index
* BackwardScanDirection: backward scan of an ordered index
Path path;
List *indexinfo;
List *indexqual;
+ List *indexjoinclauses;
ScanDirection indexscandir;
double rows; /* estimated number of result tuples */
} IndexPath;
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: restrictinfo.h,v 1.16 2002/11/24 21:52:15 tgl Exp $
+ * $Id: restrictinfo.h,v 1.17 2003/06/15 22:51:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern List *remove_redundant_join_clauses(Query *root,
List *restrictinfo_list,
JoinType jointype);
+extern List *select_nonredundant_join_clauses(Query *root,
+ List *restrictinfo_list,
+ List *reference_list,
+ JoinType jointype);
#endif /* RESTRICTINFO_H */