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path: root/src/backend/optimizer/util/relnode.c
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Diffstat (limited to 'src/backend/optimizer/util/relnode.c')
-rw-r--r--src/backend/optimizer/util/relnode.c71
1 files changed, 53 insertions, 18 deletions
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 68fd033595..8d5f7c5e8d 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -43,6 +43,7 @@ typedef struct JoinHashEntry
static void build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
RelOptInfo *input_rel,
SpecialJoinInfo *sjinfo,
+ List *pushed_down_joins,
bool can_null);
static List *build_joinrel_restrictlist(PlannerInfo *root,
RelOptInfo *joinrel,
@@ -632,6 +633,7 @@ add_join_rel(PlannerInfo *root, RelOptInfo *joinrel)
* 'outer_rel' and 'inner_rel' are relation nodes for the relations to be
* joined
* 'sjinfo': join context info
+ * 'pushed_down_joins': any pushed-down outer joins that are now completed
* 'restrictlist_ptr': result variable. If not NULL, *restrictlist_ptr
* receives the list of RestrictInfo nodes that apply to this
* particular pair of joinable relations.
@@ -645,6 +647,7 @@ build_join_rel(PlannerInfo *root,
RelOptInfo *outer_rel,
RelOptInfo *inner_rel,
SpecialJoinInfo *sjinfo,
+ List *pushed_down_joins,
List **restrictlist_ptr)
{
RelOptInfo *joinrel;
@@ -757,9 +760,9 @@ build_join_rel(PlannerInfo *root,
* and inner rels we first try to build it from. But the contents should
* be the same regardless.
*/
- build_joinrel_tlist(root, joinrel, outer_rel, sjinfo,
+ build_joinrel_tlist(root, joinrel, outer_rel, sjinfo, pushed_down_joins,
(sjinfo->jointype == JOIN_FULL));
- build_joinrel_tlist(root, joinrel, inner_rel, sjinfo,
+ build_joinrel_tlist(root, joinrel, inner_rel, sjinfo, pushed_down_joins,
(sjinfo->jointype != JOIN_INNER));
add_placeholders_to_joinrel(root, joinrel, outer_rel, inner_rel, sjinfo);
@@ -870,8 +873,8 @@ build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel,
joinrel->reloptkind = RELOPT_OTHER_JOINREL;
joinrel->relids = bms_union(outer_rel->relids, inner_rel->relids);
- if (sjinfo->ojrelid != 0)
- joinrel->relids = bms_add_member(joinrel->relids, sjinfo->ojrelid);
+ joinrel->relids = add_outer_joins_to_relids(root, joinrel->relids, sjinfo,
+ NULL);
joinrel->rows = 0;
/* cheap startup cost is interesting iff not all tuples to be retrieved */
joinrel->consider_startup = (root->tuple_fraction > 0);
@@ -1042,22 +1045,32 @@ min_join_parameterization(PlannerInfo *root,
* from this input relation. If so, we will (normally) add the join's relid
* to the nulling bitmaps of Vars and PHVs bubbled up from the input.
*
- * When forming an outer join's target list, special handling is needed
- * in case the outer join was commuted with another one per outer join
- * identity 3 (see optimizer/README). We must take steps to ensure that
- * the output Vars have the same nulling bitmaps that they would if the
- * two joins had been done in syntactic order; else they won't match Vars
- * appearing higher in the query tree. We need to do two things:
+ * When forming an outer join's target list, special handling is needed in
+ * case the outer join was commuted with another one per outer join identity 3
+ * (see optimizer/README). We must take steps to ensure that the output Vars
+ * have the same nulling bitmaps that they would if the two joins had been
+ * done in syntactic order; else they won't match Vars appearing higher in
+ * the query tree. An exception to the match-the-syntactic-order rule is
+ * that when an outer join is pushed down into another one's RHS per identity
+ * 3, we can't mark its Vars as nulled until the now-upper outer join is also
+ * completed. So we need to do three things:
*
- * First, we add the outer join's relid to the nulling bitmap only if the Var
- * or PHV actually comes from within the syntactically nullable side(s) of the
- * outer join. This takes care of the possibility that we have transformed
+ * First, we add the outer join's relid to the nulling bitmap only if the
+ * outer join has been completely performed and the Var or PHV actually
+ * comes from within the syntactically nullable side(s) of the outer join.
+ * This takes care of the possibility that we have transformed
* (A leftjoin B on (Pab)) leftjoin C on (Pbc)
* to
* A leftjoin (B leftjoin C on (Pbc)) on (Pab)
- * Here the now-upper A/B join must not mark C columns as nulled by itself.
+ * Here the pushed-down B/C join cannot mark C columns as nulled yet,
+ * while the now-upper A/B join must not mark C columns as nulled by itself.
*
- * Second, any relid in sjinfo->commute_above_r that is already part of
+ * Second, perform the same operation for each SpecialJoinInfo listed in
+ * pushed_down_joins (which, in this example, would be the B/C join when
+ * we are at the now-upper A/B join). This allows the now-upper join to
+ * complete the marking of "C" Vars that now have fully valid values.
+ *
+ * Third, any relid in sjinfo->commute_above_r that is already part of
* the joinrel is added to the nulling bitmaps of nullable Vars and PHVs.
* This takes care of the reverse case where we implement
* A leftjoin (B leftjoin C on (Pbc)) on (Pab)
@@ -1071,10 +1084,12 @@ static void
build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
RelOptInfo *input_rel,
SpecialJoinInfo *sjinfo,
+ List *pushed_down_joins,
bool can_null)
{
Relids relids = joinrel->relids;
ListCell *vars;
+ ListCell *lc;
foreach(vars, input_rel->reltarget->exprs)
{
@@ -1101,11 +1116,21 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
phv = copyObject(phv);
/* See comments above to understand this logic */
if (sjinfo->ojrelid != 0 &&
+ bms_is_member(sjinfo->ojrelid, relids) &&
(bms_is_subset(phv->phrels, sjinfo->syn_righthand) ||
(sjinfo->jointype == JOIN_FULL &&
bms_is_subset(phv->phrels, sjinfo->syn_lefthand))))
phv->phnullingrels = bms_add_member(phv->phnullingrels,
sjinfo->ojrelid);
+ foreach(lc, pushed_down_joins)
+ {
+ SpecialJoinInfo *othersj = (SpecialJoinInfo *) lfirst(lc);
+
+ Assert(bms_is_member(othersj->ojrelid, relids));
+ if (bms_is_subset(phv->phrels, othersj->syn_righthand))
+ phv->phnullingrels = bms_add_member(phv->phnullingrels,
+ othersj->ojrelid);
+ }
phv->phnullingrels =
bms_join(phv->phnullingrels,
bms_intersect(sjinfo->commute_above_r,
@@ -1166,11 +1191,21 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
var = copyObject(var);
/* See comments above to understand this logic */
if (sjinfo->ojrelid != 0 &&
+ bms_is_member(sjinfo->ojrelid, relids) &&
(bms_is_member(var->varno, sjinfo->syn_righthand) ||
(sjinfo->jointype == JOIN_FULL &&
bms_is_member(var->varno, sjinfo->syn_lefthand))))
var->varnullingrels = bms_add_member(var->varnullingrels,
sjinfo->ojrelid);
+ foreach(lc, pushed_down_joins)
+ {
+ SpecialJoinInfo *othersj = (SpecialJoinInfo *) lfirst(lc);
+
+ Assert(bms_is_member(othersj->ojrelid, relids));
+ if (bms_is_member(var->varno, othersj->syn_righthand))
+ var->varnullingrels = bms_add_member(var->varnullingrels,
+ othersj->ojrelid);
+ }
var->varnullingrels =
bms_join(var->varnullingrels,
bms_intersect(sjinfo->commute_above_r,
@@ -1259,7 +1294,7 @@ build_joinrel_restrictlist(PlannerInfo *root,
joinrel->relids,
outer_rel->relids,
inner_rel,
- sjinfo->ojrelid));
+ sjinfo));
return result;
}
@@ -1543,7 +1578,7 @@ get_baserel_parampathinfo(PlannerInfo *root, RelOptInfo *baserel,
joinrelids,
required_outer,
baserel,
- 0));
+ NULL));
/* Compute set of serial numbers of the enforced clauses */
pserials = NULL;
@@ -1666,7 +1701,7 @@ get_joinrel_parampathinfo(PlannerInfo *root, RelOptInfo *joinrel,
join_and_req,
required_outer,
joinrel,
- 0);
+ NULL);
/* We only want ones that aren't movable to lower levels */
dropped_ecs = NIL;
foreach(lc, eclauses)
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