Re: plan time of MASSIVE partitioning ...
| От | Tom Lane |
|---|---|
| Тема | Re: plan time of MASSIVE partitioning ... |
| Дата | |
| Msg-id | 24391.1288332514@sss.pgh.pa.us обсуждение исходный текст |
| Ответ на | Re: plan time of MASSIVE partitioning ... (Tom Lane <tgl@sss.pgh.pa.us>) |
| Ответы |
Re: plan time of MASSIVE partitioning ...
(Boszormenyi Zoltan <zb@cybertec.at>)
|
| Список | pgsql-hackers |
I wrote:
> the right way to make this faster is to refactor things so that we
> don't generate useless equivalence classes in the first place, or
> at least don't keep them around in the planner's lists once we realize
> they're useless.
After a bit of hacking, I propose the attached patch.
> I like Heikki's hack to cut down on searching in make_canonical_pathkey,
> but I think that complicating the data structure searching beyond that
> is just a band-aid.
With the given test case and this patch, we end up with exactly two
canonical pathkeys referencing a single EquivalenceClass. So as far
as I can tell there's not a lot of point in refining the pathkey
searching. Now, the EquivalenceClass has got 483 members, which
means that there's still some O(N^2) behavior in
get_eclass_for_sort_expr. There might be some use in refining the
search for a matching eclass member. It's not sticking out in
profiling like it did before though.
regards, tom lane
diff --git a/src/backend/optimizer/README b/src/backend/optimizer/README
index d6402cf911817b1b8c17da91019a1fac19bf051a..5c0786f2fe6dea9a72ad66ba93aa8833ab0e26ba 100644
*** a/src/backend/optimizer/README
--- b/src/backend/optimizer/README
*************** sort ordering was important; and so usin
*** 632,640 ****
orderings doesn't create any real problem.
- Though Bob Devine <bob.devine@worldnet.att.net> was not involved in the
- coding of our optimizer, he is available to field questions about
- optimizer topics.
-- bjm & tgl
--- 632,670 ----
orderings doesn't create any real problem.
+ Order of processing for EquivalenceClasses and PathKeys
+ -------------------------------------------------------
+
+ As alluded to above, there is a specific sequence of phases in the
+ processing of EquivalenceClasses and PathKeys during planning. During the
+ initial scanning of the query's quals (deconstruct_jointree followed by
+ reconsider_outer_join_clauses), we construct EquivalenceClasses based on
+ mergejoinable clauses found in the quals. At the end of this process,
+ we know all we can know about equivalence of different variables, so
+ subsequently there will be no further merging of EquivalenceClasses.
+ At that point it is possible to consider the EquivalenceClasses as
+ "canonical" and build canonical PathKeys that reference them. Before
+ we reach that point (actually, before entering query_planner at all)
+ we also ensure that we have constructed EquivalenceClasses for all the
+ expressions used in the query's ORDER BY and related clauses. These
+ classes might or might not get merged together, depending on what we
+ find in the quals.
+
+ Because all the EquivalenceClasses are known before we begin path
+ generation, we can use them as a guide to which indexes are of interest:
+ if an index's column is not mentioned in any EquivalenceClass then that
+ index's sort order cannot possibly be helpful for the query. This allows
+ short-circuiting of much of the processing of create_index_paths() for
+ irrelevant indexes.
+
+ There are some cases where planner.c constructs additional
+ EquivalenceClasses and PathKeys after query_planner has completed.
+ In these cases, the extra ECs/PKs are needed to represent sort orders
+ that were not considered during query_planner. Such situations should be
+ minimized since it is impossible for query_planner to return a plan
+ producing such a sort order, meaning a explicit sort will always be needed.
+ Currently this happens only for queries involving multiple window functions
+ with different orderings, so extra sorts are needed anyway.
-- bjm & tgl
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c
index e44e960b5454d4698ed82e4e857794ffe2a9adf2..c101c272a14b2f1b9d92a54670688df057d84a13 100644
*** a/src/backend/optimizer/path/equivclass.c
--- b/src/backend/optimizer/path/equivclass.c
*************** static bool reconsider_full_join_clause(
*** 78,83 ****
--- 78,87 ----
* join. (This is the reason why we need a failure return. It's more
* convenient to check this case here than at the call sites...)
*
+ * On success return, we have also initialized the clause's left_ec/right_ec
+ * fields to point to the EquivalenceClass built from it. This saves lookup
+ * effort later.
+ *
* Note: constructing merged EquivalenceClasses is a standard UNION-FIND
* problem, for which there exist better data structures than simple lists.
* If this code ever proves to be a bottleneck then it could be sped up ---
*************** process_equivalence(PlannerInfo *root, R
*** 106,111 ****
--- 110,119 ----
*em2;
ListCell *lc1;
+ /* Should not already be marked as having generated an eclass */
+ Assert(restrictinfo->left_ec == NULL);
+ Assert(restrictinfo->right_ec == NULL);
+
/* Extract info from given clause */
Assert(is_opclause(clause));
opno = ((OpExpr *) clause)->opno;
*************** process_equivalence(PlannerInfo *root, R
*** 236,243 ****
{
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
/* mark the RI as usable with this pair of EMs */
- /* NB: can't set left_ec/right_ec until merging is finished */
restrictinfo->left_em = em1;
restrictinfo->right_em = em2;
return true;
--- 244,253 ----
{
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as associated with this eclass */
+ restrictinfo->left_ec = ec1;
+ restrictinfo->right_ec = ec1;
/* mark the RI as usable with this pair of EMs */
restrictinfo->left_em = em1;
restrictinfo->right_em = em2;
return true;
*************** process_equivalence(PlannerInfo *root, R
*** 266,271 ****
--- 276,284 ----
ec2->ec_relids = NULL;
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as associated with this eclass */
+ restrictinfo->left_ec = ec1;
+ restrictinfo->right_ec = ec1;
/* mark the RI as usable with this pair of EMs */
restrictinfo->left_em = em1;
restrictinfo->right_em = em2;
*************** process_equivalence(PlannerInfo *root, R
*** 276,281 ****
--- 289,297 ----
em2 = add_eq_member(ec1, item2, item2_relids, false, item2_type);
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as associated with this eclass */
+ restrictinfo->left_ec = ec1;
+ restrictinfo->right_ec = ec1;
/* mark the RI as usable with this pair of EMs */
restrictinfo->left_em = em1;
restrictinfo->right_em = em2;
*************** process_equivalence(PlannerInfo *root, R
*** 286,291 ****
--- 302,310 ----
em1 = add_eq_member(ec2, item1, item1_relids, false, item1_type);
ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo);
ec2->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as associated with this eclass */
+ restrictinfo->left_ec = ec2;
+ restrictinfo->right_ec = ec2;
/* mark the RI as usable with this pair of EMs */
restrictinfo->left_em = em1;
restrictinfo->right_em = em2;
*************** process_equivalence(PlannerInfo *root, R
*** 311,316 ****
--- 330,338 ----
root->eq_classes = lappend(root->eq_classes, ec);
+ /* mark the RI as associated with this eclass */
+ restrictinfo->left_ec = ec;
+ restrictinfo->right_ec = ec;
/* mark the RI as usable with this pair of EMs */
restrictinfo->left_em = em1;
restrictinfo->right_em = em2;
*************** add_eq_member(EquivalenceClass *ec, Expr
*** 362,376 ****
/*
* get_eclass_for_sort_expr
* Given an expression and opfamily info, find an existing equivalence
! * class it is a member of; if none, build a new single-member
* EquivalenceClass for it.
*
* sortref is the SortGroupRef of the originating SortGroupClause, if any,
* or zero if not. (It should never be zero if the expression is volatile!)
*
* This can be used safely both before and after EquivalenceClass merging;
* since it never causes merging it does not invalidate any existing ECs
! * or PathKeys.
*
* Note: opfamilies must be chosen consistently with the way
* process_equivalence() would do; that is, generated from a mergejoinable
--- 384,402 ----
/*
* get_eclass_for_sort_expr
* Given an expression and opfamily info, find an existing equivalence
! * class it is a member of; if none, optionally build a new single-member
* EquivalenceClass for it.
*
* sortref is the SortGroupRef of the originating SortGroupClause, if any,
* or zero if not. (It should never be zero if the expression is volatile!)
*
+ * If create_it is TRUE, we'll build a new EquivalenceClass when there is no
+ * match. If create_it is FALSE, we just return NULL when no match.
+ *
* This can be used safely both before and after EquivalenceClass merging;
* since it never causes merging it does not invalidate any existing ECs
! * or PathKeys. However, ECs added after path generation has begun are
! * of limited usefulness, so usually it's best to create them beforehand.
*
* Note: opfamilies must be chosen consistently with the way
* process_equivalence() would do; that is, generated from a mergejoinable
*************** get_eclass_for_sort_expr(PlannerInfo *ro
*** 382,388 ****
Expr *expr,
Oid expr_datatype,
List *opfamilies,
! Index sortref)
{
EquivalenceClass *newec;
EquivalenceMember *newem;
--- 408,415 ----
Expr *expr,
Oid expr_datatype,
List *opfamilies,
! Index sortref,
! bool create_it)
{
EquivalenceClass *newec;
EquivalenceMember *newem;
*************** get_eclass_for_sort_expr(PlannerInfo *ro
*** 426,433 ****
}
}
/*
! * No match, so build a new single-member EC
*
* Here, we must be sure that we construct the EC in the right context. We
* can assume, however, that the passed expr is long-lived.
--- 453,464 ----
}
}
+ /* No match; does caller want a NULL result? */
+ if (!create_it)
+ return NULL;
+
/*
! * OK, build a new single-member EC
*
* Here, we must be sure that we construct the EC in the right context. We
* can assume, however, that the passed expr is long-lived.
*************** create_join_clause(PlannerInfo *root,
*** 1094,1101 ****
rinfo->parent_ec = parent_ec;
/*
! * We can set these now, rather than letting them be looked up later,
! * since this is only used after EC merging is complete.
*/
rinfo->left_ec = ec;
rinfo->right_ec = ec;
--- 1125,1132 ----
rinfo->parent_ec = parent_ec;
/*
! * We know the correct values for left_ec/right_ec, ie this particular EC,
! * so we can just set them directly instead of forcing another lookup.
*/
rinfo->left_ec = ec;
rinfo->right_ec = ec;
diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c
index ab3b9cd394d9af54bcd59e9830a9fbcc0a773fa8..bea134b3f1a02db8c611a6fc46d5bba041961682 100644
*** a/src/backend/optimizer/path/joinpath.c
--- b/src/backend/optimizer/path/joinpath.c
*************** select_mergejoin_clauses(PlannerInfo *ro
*** 1041,1047 ****
* mergejoin is not really all that big a deal, and so it's not clear
* that improving this is important.
*/
! cache_mergeclause_eclasses(root, restrictinfo);
if (EC_MUST_BE_REDUNDANT(restrictinfo->left_ec) ||
EC_MUST_BE_REDUNDANT(restrictinfo->right_ec))
--- 1041,1047 ----
* mergejoin is not really all that big a deal, and so it's not clear
* that improving this is important.
*/
! update_mergeclause_eclasses(root, restrictinfo);
if (EC_MUST_BE_REDUNDANT(restrictinfo->left_ec) ||
EC_MUST_BE_REDUNDANT(restrictinfo->right_ec))
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 643d57a92dc83f6adf4e2d1da223909528d59805..20c6d73617d507b88fce427a681320a684b47cd0 100644
*** a/src/backend/optimizer/path/pathkeys.c
--- b/src/backend/optimizer/path/pathkeys.c
*************** static PathKey *make_pathkey_from_sortin
*** 40,45 ****
--- 40,46 ----
Expr *expr, Oid ordering_op,
bool nulls_first,
Index sortref,
+ bool create_it,
bool canonicalize);
static Var *find_indexkey_var(PlannerInfo *root, RelOptInfo *rel,
AttrNumber varattno);
*************** canonicalize_pathkeys(PlannerInfo *root,
*** 230,235 ****
--- 231,240 ----
* If the PathKey is being generated from a SortGroupClause, sortref should be
* the SortGroupClause's SortGroupRef; otherwise zero.
*
+ * create_it is TRUE if we should create any missing EquivalenceClass
+ * needed to represent the sort key. If it's FALSE, we return NULL if the
+ * sort key isn't already present in any EquivalenceClass.
+ *
* canonicalize should always be TRUE after EquivalenceClass merging has
* been performed, but FALSE if we haven't done EquivalenceClass merging yet.
*/
*************** make_pathkey_from_sortinfo(PlannerInfo *
*** 238,243 ****
--- 243,249 ----
Expr *expr, Oid ordering_op,
bool nulls_first,
Index sortref,
+ bool create_it,
bool canonicalize)
{
Oid opfamily,
*************** make_pathkey_from_sortinfo(PlannerInfo *
*** 300,308 ****
COERCE_DONTCARE);
}
! /* Now find or create a matching EquivalenceClass */
eclass = get_eclass_for_sort_expr(root, expr, opcintype, opfamilies,
! sortref);
/* And finally we can find or create a PathKey node */
if (canonicalize)
--- 306,318 ----
COERCE_DONTCARE);
}
! /* Now find or (optionally) create a matching EquivalenceClass */
eclass = get_eclass_for_sort_expr(root, expr, opcintype, opfamilies,
! sortref, create_it);
!
! /* Fail if no EC and !create_it */
! if (!eclass)
! return NULL;
/* And finally we can find or create a PathKey node */
if (canonicalize)
*************** get_cheapest_fractional_path_for_pathkey
*** 478,485 ****
* The result is canonical, meaning that redundant pathkeys are removed;
* it may therefore have fewer entries than there are index columns.
*
! * We generate the full pathkeys list whether or not all are useful for the
! * current query. Caller should do truncate_useless_pathkeys().
*/
List *
build_index_pathkeys(PlannerInfo *root,
--- 488,498 ----
* The result is canonical, meaning that redundant pathkeys are removed;
* it may therefore have fewer entries than there are index columns.
*
! * Another reason for stopping early is that we may be able to tell that
! * an index column's sort order is uninteresting for this query. However,
! * that test is just based on the existence of an EquivalenceClass and not
! * on position in pathkey lists, so it's not complete. Caller should call
! * truncate_useless_pathkeys() to possibly remove more pathkeys.
*/
List *
build_index_pathkeys(PlannerInfo *root,
*************** build_index_pathkeys(PlannerInfo *root,
*** 527,540 ****
indexprs_item = lnext(indexprs_item);
}
! /* OK, make a canonical pathkey for this sort key */
cpathkey = make_pathkey_from_sortinfo(root,
indexkey,
sortop,
nulls_first,
0,
true);
/* Add to list unless redundant */
if (!pathkey_is_redundant(cpathkey, retval))
retval = lappend(retval, cpathkey);
--- 540,562 ----
indexprs_item = lnext(indexprs_item);
}
! /* OK, try to make a canonical pathkey for this sort key */
cpathkey = make_pathkey_from_sortinfo(root,
indexkey,
sortop,
nulls_first,
0,
+ false,
true);
+ /*
+ * If the sort key isn't already present in any EquivalenceClass,
+ * then it's not an interesting sort order for this query. So
+ * we can stop now --- lower-order sort keys aren't useful either.
+ */
+ if (!cpathkey)
+ break;
+
/* Add to list unless redundant */
if (!pathkey_is_redundant(cpathkey, retval))
retval = lappend(retval, cpathkey);
*************** convert_subquery_pathkeys(PlannerInfo *r
*** 644,656 ****
outer_expr,
sub_member->em_datatype,
sub_eclass->ec_opfamilies,
! 0);
! best_pathkey =
! make_canonical_pathkey(root,
! outer_ec,
! sub_pathkey->pk_opfamily,
! sub_pathkey->pk_strategy,
! sub_pathkey->pk_nulls_first);
}
}
else
--- 666,685 ----
outer_expr,
sub_member->em_datatype,
sub_eclass->ec_opfamilies,
! 0,
! false);
!
! /*
! * If we don't find a matching EC, sub-pathkey isn't
! * interesting to the outer query
! */
! if (outer_ec)
! best_pathkey =
! make_canonical_pathkey(root,
! outer_ec,
! sub_pathkey->pk_opfamily,
! sub_pathkey->pk_strategy,
! sub_pathkey->pk_nulls_first);
}
}
else
*************** convert_subquery_pathkeys(PlannerInfo *r
*** 738,744 ****
outer_expr,
sub_member->em_datatype,
sub_eclass->ec_opfamilies,
! 0);
outer_pk = make_canonical_pathkey(root,
outer_ec,
sub_pathkey->pk_opfamily,
--- 767,782 ----
outer_expr,
sub_member->em_datatype,
sub_eclass->ec_opfamilies,
! 0,
! false);
!
! /*
! * If we don't find a matching EC, this sub-pathkey isn't
! * interesting to the outer query
! */
! if (!outer_ec)
! continue;
!
outer_pk = make_canonical_pathkey(root,
outer_ec,
sub_pathkey->pk_opfamily,
*************** make_pathkeys_for_sortclauses(PlannerInf
*** 859,864 ****
--- 897,903 ----
sortcl->sortop,
sortcl->nulls_first,
sortcl->tleSortGroupRef,
+ true,
canonicalize);
/* Canonical form eliminates redundant ordering keys */
*************** make_pathkeys_for_sortclauses(PlannerInf
*** 878,923 ****
****************************************************************************/
/*
! * cache_mergeclause_eclasses
! * Make the cached EquivalenceClass links valid in a mergeclause
! * restrictinfo.
*
* RestrictInfo contains fields in which we may cache pointers to
* EquivalenceClasses for the left and right inputs of the mergeclause.
* (If the mergeclause is a true equivalence clause these will be the
! * same EquivalenceClass, otherwise not.)
*/
void
! cache_mergeclause_eclasses(PlannerInfo *root, RestrictInfo *restrictinfo)
{
Assert(restrictinfo->mergeopfamilies != NIL);
! /* the cached values should be either both set or both not */
! if (restrictinfo->left_ec == NULL)
! {
! Expr *clause = restrictinfo->clause;
! Oid lefttype,
! righttype;
! /* Need the declared input types of the operator */
! op_input_types(((OpExpr *) clause)->opno, &lefttype, &righttype);
! /* Find or create a matching EquivalenceClass for each side */
! restrictinfo->left_ec =
! get_eclass_for_sort_expr(root,
! (Expr *) get_leftop(clause),
! lefttype,
! restrictinfo->mergeopfamilies,
! 0);
! restrictinfo->right_ec =
! get_eclass_for_sort_expr(root,
! (Expr *) get_rightop(clause),
! righttype,
! restrictinfo->mergeopfamilies,
! 0);
! }
! else
! Assert(restrictinfo->right_ec != NULL);
}
/*
--- 917,997 ----
****************************************************************************/
/*
! * initialize_mergeclause_eclasses
! * Set the EquivalenceClass links in a mergeclause restrictinfo.
*
* RestrictInfo contains fields in which we may cache pointers to
* EquivalenceClasses for the left and right inputs of the mergeclause.
* (If the mergeclause is a true equivalence clause these will be the
! * same EquivalenceClass, otherwise not.) If the mergeclause is either
! * used to generate an EquivalenceClass, or derived from an EquivalenceClass,
! * then it's easy to set up the left_ec and right_ec members --- otherwise,
! * this function should be called to set them up. We will generate new
! * EquivalenceClauses if necessary to represent the mergeclause's left and
! * right sides.
! *
! * Note this is called before EC merging is complete, so the links won't
! * necessarily point to canonical ECs. Before they are actually used for
! * anything, update_mergeclause_eclasses must be called to ensure that
! * they've been updated to point to canonical ECs.
*/
void
! initialize_mergeclause_eclasses(PlannerInfo *root, RestrictInfo *restrictinfo)
{
+ Expr *clause = restrictinfo->clause;
+ Oid lefttype,
+ righttype;
+
+ /* Should be a mergeclause ... */
Assert(restrictinfo->mergeopfamilies != NIL);
+ /* ... with links not yet set */
+ Assert(restrictinfo->left_ec == NULL);
+ Assert(restrictinfo->right_ec == NULL);
! /* Need the declared input types of the operator */
! op_input_types(((OpExpr *) clause)->opno, &lefttype, &righttype);
! /* Find or create a matching EquivalenceClass for each side */
! restrictinfo->left_ec =
! get_eclass_for_sort_expr(root,
! (Expr *) get_leftop(clause),
! lefttype,
! restrictinfo->mergeopfamilies,
! 0,
! true);
! restrictinfo->right_ec =
! get_eclass_for_sort_expr(root,
! (Expr *) get_rightop(clause),
! righttype,
! restrictinfo->mergeopfamilies,
! 0,
! true);
! }
! /*
! * update_mergeclause_eclasses
! * Make the cached EquivalenceClass links valid in a mergeclause
! * restrictinfo.
! *
! * These pointers should have been set by process_equivalence or
! * initialize_mergeclause_eclasses, but they might have been set to
! * non-canonical ECs that got merged later. Chase up to the canonical
! * merged parent if so.
! */
! void
! update_mergeclause_eclasses(PlannerInfo *root, RestrictInfo *restrictinfo)
! {
! /* Should be a merge clause ... */
! Assert(restrictinfo->mergeopfamilies != NIL);
! /* ... with pointers already set */
! Assert(restrictinfo->left_ec != NULL);
! Assert(restrictinfo->right_ec != NULL);
!
! /* Chase up to the top as needed */
! while (restrictinfo->left_ec->ec_merged)
! restrictinfo->left_ec = restrictinfo->left_ec->ec_merged;
! while (restrictinfo->right_ec->ec_merged)
! restrictinfo->right_ec = restrictinfo->right_ec->ec_merged;
}
/*
*************** find_mergeclauses_for_pathkeys(PlannerIn
*** 953,959 ****
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(i);
! cache_mergeclause_eclasses(root, rinfo);
}
foreach(i, pathkeys)
--- 1027,1033 ----
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(i);
! update_mergeclause_eclasses(root, rinfo);
}
foreach(i, pathkeys)
*************** select_outer_pathkeys_for_merge(PlannerI
*** 1089,1095 ****
ListCell *lc2;
/* get the outer eclass */
! cache_mergeclause_eclasses(root, rinfo);
if (rinfo->outer_is_left)
oeclass = rinfo->left_ec;
--- 1163,1169 ----
ListCell *lc2;
/* get the outer eclass */
! update_mergeclause_eclasses(root, rinfo);
if (rinfo->outer_is_left)
oeclass = rinfo->left_ec;
*************** make_inner_pathkeys_for_merge(PlannerInf
*** 1250,1256 ****
EquivalenceClass *ieclass;
PathKey *pathkey;
! cache_mergeclause_eclasses(root, rinfo);
if (rinfo->outer_is_left)
{
--- 1324,1330 ----
EquivalenceClass *ieclass;
PathKey *pathkey;
! update_mergeclause_eclasses(root, rinfo);
if (rinfo->outer_is_left)
{
*************** pathkeys_useful_for_merging(PlannerInfo
*** 1366,1372 ****
if (restrictinfo->mergeopfamilies == NIL)
continue;
! cache_mergeclause_eclasses(root, restrictinfo);
if (pathkey->pk_eclass == restrictinfo->left_ec ||
pathkey->pk_eclass == restrictinfo->right_ec)
--- 1440,1446 ----
if (restrictinfo->mergeopfamilies == NIL)
continue;
! update_mergeclause_eclasses(root, restrictinfo);
if (pathkey->pk_eclass == restrictinfo->left_ec ||
pathkey->pk_eclass == restrictinfo->right_ec)
diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c
index a2ff314679daa30003d59d04ec01066049e1cb13..77ebadd5cc6a634f5e07886c19a3e4c71dbe3c31 100644
*** a/src/backend/optimizer/plan/initsplan.c
--- b/src/backend/optimizer/plan/initsplan.c
*************** distribute_qual_to_rels(PlannerInfo *roo
*** 1066,1071 ****
--- 1066,1077 ----
*
* If none of the above hold, pass it off to
* distribute_restrictinfo_to_rels().
+ *
+ * In all cases, it's important to initialize the left_ec and right_ec
+ * fields of a mergejoinable clause, so that all possibly mergejoinable
+ * expressions have representations in EquivalenceClasses. If
+ * process_equivalence is successful, it will take care of that;
+ * otherwise, we have to call initialize_mergeclause_eclasses to do it.
*/
if (restrictinfo->mergeopfamilies)
{
*************** distribute_qual_to_rels(PlannerInfo *roo
*** 1073,1082 ****
{
if (process_equivalence(root, restrictinfo, below_outer_join))
return;
! /* EC rejected it, so pass to distribute_restrictinfo_to_rels */
}
else if (maybe_outer_join && restrictinfo->can_join)
{
if (bms_is_subset(restrictinfo->left_relids,
outerjoin_nonnullable) &&
!bms_overlap(restrictinfo->right_relids,
--- 1079,1093 ----
{
if (process_equivalence(root, restrictinfo, below_outer_join))
return;
! /* EC rejected it, so set left_ec/right_ec the hard way ... */
! initialize_mergeclause_eclasses(root, restrictinfo);
! /* ... and fall through to distribute_restrictinfo_to_rels */
}
else if (maybe_outer_join && restrictinfo->can_join)
{
+ /* we need to set up left_ec/right_ec the hard way */
+ initialize_mergeclause_eclasses(root, restrictinfo);
+ /* now see if it should go to any outer-join lists */
if (bms_is_subset(restrictinfo->left_relids,
outerjoin_nonnullable) &&
!bms_overlap(restrictinfo->right_relids,
*************** distribute_qual_to_rels(PlannerInfo *roo
*** 1104,1109 ****
--- 1115,1126 ----
restrictinfo);
return;
}
+ /* nope, so fall through to distribute_restrictinfo_to_rels */
+ }
+ else
+ {
+ /* we still need to set up left_ec/right_ec */
+ initialize_mergeclause_eclasses(root, restrictinfo);
}
}
*************** process_implied_equality(PlannerInfo *ro
*** 1404,1409 ****
--- 1421,1429 ----
*
* This overlaps the functionality of process_implied_equality(), but we
* must return the RestrictInfo, not push it into the joininfo tree.
+ *
+ * Note: we do not do initialize_mergeclause_eclasses() here. It is
+ * caller's responsibility that left_ec/right_ec be set as necessary.
*/
RestrictInfo *
build_implied_join_equality(Oid opno,
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 5f628eeeb96174a3c9051257e235baff43efcacd..6bce53cce57d5c3d8551ad12c371e36100c009ff 100644
*** a/src/include/optimizer/paths.h
--- b/src/include/optimizer/paths.h
*************** extern EquivalenceClass *get_eclass_for_
*** 116,122 ****
Expr *expr,
Oid expr_datatype,
List *opfamilies,
! Index sortref);
extern void generate_base_implied_equalities(PlannerInfo *root);
extern List *generate_join_implied_equalities(PlannerInfo *root,
RelOptInfo *joinrel,
--- 116,123 ----
Expr *expr,
Oid expr_datatype,
List *opfamilies,
! Index sortref,
! bool create_it);
extern void generate_base_implied_equalities(PlannerInfo *root);
extern List *generate_join_implied_equalities(PlannerInfo *root,
RelOptInfo *joinrel,
*************** extern List *make_pathkeys_for_sortclaus
*** 172,178 ****
List *sortclauses,
List *tlist,
bool canonicalize);
! extern void cache_mergeclause_eclasses(PlannerInfo *root,
RestrictInfo *restrictinfo);
extern List *find_mergeclauses_for_pathkeys(PlannerInfo *root,
List *pathkeys,
--- 173,181 ----
List *sortclauses,
List *tlist,
bool canonicalize);
! extern void initialize_mergeclause_eclasses(PlannerInfo *root,
! RestrictInfo *restrictinfo);
! extern void update_mergeclause_eclasses(PlannerInfo *root,
RestrictInfo *restrictinfo);
extern List *find_mergeclauses_for_pathkeys(PlannerInfo *root,
List *pathkeys,
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