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Fix some issues with LATERAL(SELECT UNION ALL SELECT).

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The LATERAL marking has to be propagated down to the UNION leaf queries
when we pull them up.  Also, fix the formerly stubbed-off
set_append_rel_pathlist().  It does already have enough smarts to cope with
making a parameterized Append path at need; it just has to not assume that
there *must* be an unparameterized path.
This commit is contained in:
Tom Lane
2012-08-11 18:42:20 -04:00
parent 83af58f6b5
commit e76af54137
4 changed files with 94 additions and 30 deletions
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50
src/backend/optimizer/path/allpaths.c
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@ -661,6 +661,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
int parentRTindex = rti;
List *live_childrels = NIL;
List *subpaths = NIL;
bool subpaths_valid = true;
List *all_child_pathkeys = NIL;
List *all_child_outers = NIL;
ListCell *l;
@ -699,19 +700,21 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
if (IS_DUMMY_REL(childrel))
continue;
/* XXX need to figure out what to do for LATERAL */
if (childrel->cheapest_total_path == NULL)
elog(ERROR, "LATERAL within an append relation is not supported yet");
/*
* Child is live, so add it to the live_childrels list for use below.
*/
live_childrels = lappend(live_childrels, childrel);
/*
* Child is live, so add its cheapest access path to the Append path
* we are constructing for the parent.
* If child has an unparameterized cheapest-total path, add that to
* the unparameterized Append path we are constructing for the parent.
* If not, there's no workable unparameterized path.
*/
subpaths = accumulate_append_subpath(subpaths,
if (childrel->cheapest_total_path)
subpaths = accumulate_append_subpath(subpaths,
childrel->cheapest_total_path);
/* Remember which childrels are live, for logic below */
live_childrels = lappend(live_childrels, childrel);
else
subpaths_valid = false;
/*
* Collect lists of all the available path orderings and
@ -779,17 +782,20 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
}
/*
* Next, build an unordered, unparameterized Append path for the rel.
* (Note: this is correct even if we have zero or one live subpath due to
* constraint exclusion.)
* If we found unparameterized paths for all children, build an unordered,
* unparameterized Append path for the rel. (Note: this is correct even
* if we have zero or one live subpath due to constraint exclusion.)
*/
add_path(rel, (Path *) create_append_path(rel, subpaths, NULL));
if (subpaths_valid)
add_path(rel, (Path *) create_append_path(rel, subpaths, NULL));
/*
* Build unparameterized MergeAppend paths based on the collected list of
* child pathkeys.
* Also build unparameterized MergeAppend paths based on the collected
* list of child pathkeys.
*/
generate_mergeappend_paths(root, rel, live_childrels, all_child_pathkeys);
if (subpaths_valid)
generate_mergeappend_paths(root, rel, live_childrels,
all_child_pathkeys);
/*
* Build Append paths for each parameterization seen among the child rels.
@ -807,11 +813,11 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
foreach(l, all_child_outers)
{
Relids required_outer = (Relids) lfirst(l);
bool ok = true;
ListCell *lcr;
/* Select the child paths for an Append with this parameterization */
subpaths = NIL;
subpaths_valid = true;
foreach(lcr, live_childrels)
{
RelOptInfo *childrel = (RelOptInfo *) lfirst(lcr);
@ -831,7 +837,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
required_outer, 1.0);
if (cheapest_total == NULL)
{
ok = false;
subpaths_valid = false;
break;
}
}
@ -839,7 +845,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
subpaths = accumulate_append_subpath(subpaths, cheapest_total);
}
if (ok)
if (subpaths_valid)
add_path(rel, (Path *)
create_append_path(rel, subpaths, required_outer));
}
@ -911,13 +917,11 @@ generate_mergeappend_paths(PlannerInfo *root, RelOptInfo *rel,
*/
if (cheapest_startup == NULL || cheapest_total == NULL)
{
/* XXX need to figure out what to do for LATERAL */
if (childrel->cheapest_total_path == NULL)
elog(ERROR, "LATERAL within an append relation is not supported yet");
cheapest_startup = cheapest_total =
childrel->cheapest_total_path;
/* Assert we do have an unparameterized path for this child */
Assert(cheapest_total != NULL);
Assert(cheapest_total->param_info == NULL);
}
/*