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Simplify the planner's join clause management by storing join clauses

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of a relation in a flat 'joininfo' list.  The former arrangement grouped
the join clauses according to the set of unjoined relids used in each;
however, profiling on test cases involving lots of joins proves that
that data structure is a net loss.  It takes more time to group the
join clauses together than is saved by avoiding duplicate tests later.
It doesn't help any that there are usually not more than one or two
clauses per group ...
This commit is contained in:
Tom Lane
2005-06-09 04:19:00 +00:00
parent c51815afed
commit a31ad27fc5
19 changed files with 285 additions and 465 deletions
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178
src/backend/optimizer/path/indxpath.c
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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.181 2005/06/05 22:32:55 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.182 2005/06/09 04:18:59 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -71,8 +71,6 @@ static Oid indexable_operator(Expr *clause, Oid opclass,
static bool pred_test_recurse(Node *clause, Node *predicate);
static bool pred_test_simple_clause(Expr *predicate, Node *clause);
static Relids indexable_outerrelids(RelOptInfo *rel);
static bool list_matches_any_index(List *clauses, RelOptInfo *rel,
Relids outer_relids);
static bool matches_any_index(RestrictInfo *rinfo, RelOptInfo *rel,
Relids outer_relids);
static List *find_clauses_for_join(PlannerInfo *root, RelOptInfo *rel,
@ -908,7 +906,7 @@ pred_test(List *predicate_list, List *restrictinfo_list)
* classes over equi-joined attributes (i.e., if it recognized that a
* qualification such as "where a.b=c.d and a.b=5" could make use of
* an index on c.d), then we could use that equivalence class info
* here with joininfo_list to do more complete tests for the usability
* here with joininfo lists to do more complete tests for the usability
* of a partial index. For now, the test only uses restriction
* clauses (those in restrictinfo_list). --Nels, Dec '92
*
@ -1550,84 +1548,30 @@ indexable_outerrelids(RelOptInfo *rel)
Relids outer_relids = NULL;
ListCell *l;
/*
* Examine each joinclause in the joininfo list to see if it matches any
* key of any index. If so, add the clause's other rels to the result.
* (Note: we consider only actual participants, not extraneous rels
* possibly mentioned in required_relids.)
*/
foreach(l, rel->joininfo)
{
JoinInfo *joininfo = (JoinInfo *) lfirst(l);
RestrictInfo *joininfo = (RestrictInfo *) lfirst(l);
Relids other_rels;
/*
* Examine each joinclause in the JoinInfo node's list to see if
* it matches any key of any index. If so, add the JoinInfo's
* otherrels to the result. We can skip examining other
* joinclauses in the same list as soon as we find a match, since
* by definition they all have the same otherrels.
*/
if (list_matches_any_index(joininfo->jinfo_restrictinfo,
rel,
joininfo->unjoined_relids))
outer_relids = bms_add_members(outer_relids,
joininfo->unjoined_relids);
other_rels = bms_difference(joininfo->clause_relids, rel->relids);
if (matches_any_index(joininfo, rel, other_rels))
outer_relids = bms_join(outer_relids, other_rels);
else
bms_free(other_rels);
}
return outer_relids;
}
/*
* list_matches_any_index
* Workhorse for indexable_outerrelids: given a list of RestrictInfos,
* see if any of them match any index of the given rel.
*
* We define it like this so that we can recurse into OR subclauses.
*/
static bool
list_matches_any_index(List *clauses, RelOptInfo *rel, Relids outer_relids)
{
ListCell *l;
foreach(l, clauses)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
ListCell *j;
Assert(IsA(rinfo, RestrictInfo));
/* RestrictInfos that aren't ORs are easy */
if (!restriction_is_or_clause(rinfo))
{
if (matches_any_index(rinfo, rel, outer_relids))
return true;
continue;
}
foreach(j, ((BoolExpr *) rinfo->orclause)->args)
{
Node *orarg = (Node *) lfirst(j);
/* OR arguments should be ANDs or sub-RestrictInfos */
if (and_clause(orarg))
{
List *andargs = ((BoolExpr *) orarg)->args;
/* Recurse to examine AND items and sub-ORs */
if (list_matches_any_index(andargs, rel, outer_relids))
return true;
}
else
{
Assert(IsA(orarg, RestrictInfo));
Assert(!restriction_is_or_clause((RestrictInfo *) orarg));
if (matches_any_index((RestrictInfo *) orarg, rel,
outer_relids))
return true;
}
}
}
return false;
}
/*
* matches_any_index
* Workhorse for indexable_outerrelids: see if a simple joinclause can be
* Workhorse for indexable_outerrelids: see if a joinclause can be
* matched to any index of the given rel.
*/
static bool
@ -1635,6 +1579,42 @@ matches_any_index(RestrictInfo *rinfo, RelOptInfo *rel, Relids outer_relids)
{
ListCell *l;
Assert(IsA(rinfo, RestrictInfo));
if (restriction_is_or_clause(rinfo))
{
foreach(l, ((BoolExpr *) rinfo->orclause)->args)
{
Node *orarg = (Node *) lfirst(l);
/* OR arguments should be ANDs or sub-RestrictInfos */
if (and_clause(orarg))
{
ListCell *j;
/* Recurse to examine AND items and sub-ORs */
foreach(j, ((BoolExpr *) orarg)->args)
{
RestrictInfo *arinfo = (RestrictInfo *) lfirst(j);
if (matches_any_index(arinfo, rel, outer_relids))
return true;
}
}
else
{
/* Recurse to examine simple clause */
Assert(IsA(orarg, RestrictInfo));
Assert(!restriction_is_or_clause((RestrictInfo *) orarg));
if (matches_any_index((RestrictInfo *) orarg, rel,
outer_relids))
return true;
}
}
return false;
}
/* Normal case for a simple restriction clause */
foreach(l, rel->indexlist)
{
@ -1833,7 +1813,7 @@ find_clauses_for_join(PlannerInfo *root, RelOptInfo *rel,
{
List *clause_list = NIL;
bool jfound = false;
int numsources;
Relids join_relids;
ListCell *l;
/*
@ -1854,46 +1834,33 @@ find_clauses_for_join(PlannerInfo *root, RelOptInfo *rel,
clause_list = lappend(clause_list, rinfo);
}
/* found anything in base restrict list? */
numsources = (clause_list != NIL) ? 1 : 0;
/* Look for joinclauses that are usable with given outer_relids */
join_relids = bms_union(rel->relids, outer_relids);
foreach(l, rel->joininfo)
{
JoinInfo *joininfo = (JoinInfo *) lfirst(l);
bool jfoundhere = false;
ListCell *j;
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
if (!bms_is_subset(joininfo->unjoined_relids, outer_relids))
/* Can't use pushed-down clauses in outer join */
if (isouterjoin && rinfo->is_pushed_down)
continue;
if (!bms_is_subset(rinfo->required_relids, join_relids))
continue;
foreach(j, joininfo->jinfo_restrictinfo)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(j);
/* Can't use pushed-down clauses in outer join */
if (isouterjoin && rinfo->is_pushed_down)
continue;
clause_list = lappend(clause_list, rinfo);
if (!jfoundhere)
{
jfoundhere = true;
jfound = true;
numsources++;
}
}
clause_list = lappend(clause_list, rinfo);
jfound = true;
}
bms_free(join_relids);
/* if no join clause was matched then forget it, per comments above */
if (!jfound)
return NIL;
/*
* If we found clauses in more than one list, we may now have
* clauses that are known redundant. Get rid of 'em.
* We may now have clauses that are known redundant. Get rid of 'em.
*/
if (numsources > 1)
if (list_length(clause_list) > 1)
{
clause_list = remove_redundant_join_clauses(root,
clause_list,
@ -2304,7 +2271,8 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups)
{
resultquals = lappend(resultquals,
make_restrictinfo(boolqual,
true, true));
true, true,
NULL));
continue;
}
}
@ -2553,7 +2521,7 @@ prefix_quals(Node *leftop, Oid opclass,
elog(ERROR, "no = operator for opclass %u", opclass);
expr = make_opclause(oproid, BOOLOID, false,
(Expr *) leftop, (Expr *) prefix_const);
result = list_make1(make_restrictinfo(expr, true, true));
result = list_make1(make_restrictinfo(expr, true, true, NULL));
return result;
}
@ -2568,7 +2536,7 @@ prefix_quals(Node *leftop, Oid opclass,
elog(ERROR, "no >= operator for opclass %u", opclass);
expr = make_opclause(oproid, BOOLOID, false,
(Expr *) leftop, (Expr *) prefix_const);
result = list_make1(make_restrictinfo(expr, true, true));
result = list_make1(make_restrictinfo(expr, true, true, NULL));
/*-------
* If we can create a string larger than the prefix, we can say
@ -2584,7 +2552,7 @@ prefix_quals(Node *leftop, Oid opclass,
elog(ERROR, "no < operator for opclass %u", opclass);
expr = make_opclause(oproid, BOOLOID, false,
(Expr *) leftop, (Expr *) greaterstr);
result = lappend(result, make_restrictinfo(expr, true, true));
result = lappend(result, make_restrictinfo(expr, true, true, NULL));
}
return result;
@ -2655,7 +2623,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
(Expr *) leftop,
(Expr *) makeConst(datatype, -1, opr1right,
false, false));
result = list_make1(make_restrictinfo(expr, true, true));
result = list_make1(make_restrictinfo(expr, true, true, NULL));
/* create clause "key <= network_scan_last( rightop )" */
@ -2670,7 +2638,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
(Expr *) leftop,
(Expr *) makeConst(datatype, -1, opr2right,
false, false));
result = lappend(result, make_restrictinfo(expr, true, true));
result = lappend(result, make_restrictinfo(expr, true, true, NULL));
return result;
}