Yulin PEI <ype...@connect.ust.hk> writes:
> Yes, I agree because (IsNormalProcessingMode() ) means that current process
> is not in bootstrap mode and postmaster process will not build index.
> So my new modified patch is attached.
This is a good catch, but the proposed fix still seems pretty random
and unlike how it's done elsewhere. It seems to me that since
index_build() is relying on plan_create_index_workers() to assess
parallel safety, that's where to check IsUnderPostmaster. Moreover,
the existing code in compute_parallel_vacuum_workers (which gets
this right) associates the IsUnderPostmaster check with the initial
check on max_parallel_maintenance_workers. So I think that the
right fix is to adopt the compute_parallel_vacuum_workers coding
in plan_create_index_workers, and thereby create a model for future
uses of max_parallel_maintenance_workers to follow.
regards, tom lane
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 247f7d4625..1a94b58f8b 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -6375,8 +6375,11 @@ plan_create_index_workers(Oid tableOid, Oid indexOid)
double reltuples;
double allvisfrac;
- /* Return immediately when parallelism disabled */
- if (max_parallel_maintenance_workers == 0)
+ /*
+ * We don't allow performing parallel operation in standalone backend or
+ * when parallelism is disabled.
+ */
+ if (!IsUnderPostmaster || max_parallel_maintenance_workers == 0)
return 0;
/* Set up largely-dummy planner state */
