diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 66e098f488a..d14ef31eae2 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -1087,6 +1087,8 @@ bool is_parallel_safe(PlannerInfo *root, Node *node) { max_parallel_hazard_context context; + PlannerInfo *proot; + ListCell *l; /* * Even if the original querytree contained nothing unsafe, we need to @@ -1101,6 +1103,25 @@ is_parallel_safe(PlannerInfo *root, Node *node) context.max_hazard = PROPARALLEL_SAFE; context.max_interesting = PROPARALLEL_RESTRICTED; context.safe_param_ids = NIL; + + /* + * The params that refer to the same or parent query level are considered + * parallel-safe. The idea is that we compute such params at Gather or + * Gather Merge node and pass their value to workers. + */ + for (proot = root; proot != NULL; proot = proot->parent_root) + { + foreach(l, proot->init_plans) + { + SubPlan *initsubplan = (SubPlan *) lfirst(l); + ListCell *l2; + + foreach(l2, initsubplan->setParam) + context.safe_param_ids = lcons_int(lfirst_int(l2), + context.safe_param_ids); + } + } + return !max_parallel_hazard_walker(node, &context); } @@ -1225,7 +1246,8 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context) * We can't pass Params to workers at the moment either, so they are also * parallel-restricted, unless they are PARAM_EXTERN Params or are * PARAM_EXEC Params listed in safe_param_ids, meaning they could be - * generated within the worker. + * either generated within the worker or can be computed in master and + * then their value can be passed to the worker. */ else if (IsA(node, Param)) { |