Fix parallel index builds for dynamic_shared_memory_type=none.

robertmhaas · robertmhaas · commit 88ef48c1ccee · 2018-02-12T12:55:12.000-05:00
The previous code failed to realize that this setting effectively disables parallelism, and would crash if it decided to attempt parallelism anyway. Instead, treat it as a disabling condition. Kyotaro Horiguchi, who also reported the issue. Reviewed by Michael Paquier and Peter Geoghegan. Discussion: http://postgr.es/m/20180209.170635.256350357.horiguchi.kyotaro@lab.ntt.co.jp
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
@@ -5825,7 +5825,8 @@ plan_create_index_workers(Oid tableOid, Oid indexOid)
 	double		allvisfrac;
 
 	/* Return immediately when parallelism disabled */
-	if (max_parallel_maintenance_workers == 0)
+	if (dynamic_shared_memory_type == DSM_IMPL_NONE ||
+		max_parallel_maintenance_workers == 0)
 		return 0;
 
 	/* Set up largely-dummy planner state */
