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Adjust nestloop-with-inner-indexscan plan generation so that we catch

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some cases of redundant clauses that were formerly not caught.  We have
to special-case this because the clauses involved never get attached to
the same join restrictlist and so the existing logic does not notice
that they are redundant.
This commit is contained in:
Tom Lane
2003-06-15 22:51:45 +00:00
parent 3fb6f1347f
commit cb02610e50
10 changed files with 284 additions and 137 deletions
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63
src/backend/optimizer/path/indxpath.c
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@ -9,7 +9,7 @@
*
*
* 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 $
*
*-------------------------------------------------------------------------
*/
@ -59,10 +59,10 @@ static bool match_or_subclause_to_indexkey(RelOptInfo *rel,
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,
@ -583,8 +583,10 @@ group_clauses_by_indexkey(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;
@ -629,6 +631,24 @@ group_clauses_by_indexkey_for_join(RelOptInfo *rel, IndexOptInfo *index,
}
}
/*
* 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)
{
@ -1461,9 +1481,11 @@ best_inner_indexscan(Query *root, RelOptInfo *rel,
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)
{
@ -1520,7 +1542,7 @@ make_innerjoin_index_path(Query *root,
*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;
@ -1535,12 +1557,25 @@ make_innerjoin_index_path(Query *root,
/* Convert RestrictInfo nodes to indexquals the executor can handle */
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;
@ -1558,17 +1593,9 @@ make_innerjoin_index_path(Query *root,
* 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,