database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-28 18:48:04 +03:00
Code Activity

Allow asynchronous execution in more cases.

Browse Source 
In commit 27e1f1456, create_append_plan() only allowed the subplan
created from a given subpath to be executed asynchronously when it was
an async-capable ForeignPath.  To extend coverage, this patch handles
cases when the given subpath includes some other Path types as well that
can be omitted in the plan processing, such as a ProjectionPath directly
atop an async-capable ForeignPath, allowing asynchronous execution in
partitioned-scan/partitioned-join queries with non-Var tlist expressions
and more UNION queries.

Andrey Lepikhov and Etsuro Fujita, reviewed by Alexander Pyhalov and
Zhihong Yu.

Discussion: https://postgr.es/m/659c37a8-3e71-0ff2-394c-f04428c76f08%40postgrespro.ru
This commit is contained in:
Etsuro Fujita
2022-04-06 15:45:00 +09:00
parent 376dc437de
commit c2bb02bc2e
9 changed files with 287 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
src/backend/optimizer/plan/setrefs.c
View File

@@ -115,7 +115,6 @@ static Plan *set_indexonlyscan_references(PlannerInfo *root,
static Plan *set_subqueryscan_references(PlannerInfo *root,
SubqueryScan *plan,
int rtoffset);
static bool trivial_subqueryscan(SubqueryScan *plan);
static Plan *clean_up_removed_plan_level(Plan *parent, Plan *child);
static void set_foreignscan_references(PlannerInfo *root,
ForeignScan *fscan,
@@ -1319,14 +1318,26 @@ set_subqueryscan_references(PlannerInfo *root,
*
* We can delete it if it has no qual to check and the targetlist just
* regurgitates the output of the child plan.
*
* This might be called repeatedly on a SubqueryScan node, so we cache the
* result in the SubqueryScan node to avoid repeated computation.
*/
static bool
bool
trivial_subqueryscan(SubqueryScan *plan)
{
int attrno;
ListCell *lp,
*lc;
/* We might have detected this already (see mark_async_capable_plan) */
if (plan->scanstatus == SUBQUERY_SCAN_TRIVIAL)
return true;
if (plan->scanstatus == SUBQUERY_SCAN_NONTRIVIAL)
return false;
Assert(plan->scanstatus == SUBQUERY_SCAN_UNKNOWN);
/* Initially, mark the SubqueryScan as non-deletable from the plan tree */
plan->scanstatus = SUBQUERY_SCAN_NONTRIVIAL;
if (plan->scan.plan.qual != NIL)
return false;
@@ -1368,6 +1379,9 @@ trivial_subqueryscan(SubqueryScan *plan)
attrno++;
}
/* Re-mark the SubqueryScan as deletable from the plan tree */
plan->scanstatus = SUBQUERY_SCAN_TRIVIAL;
return true;
}