diff options
Diffstat (limited to 'src/backend/executor/nodeAppend.c')
| -rw-r--r-- | src/backend/executor/nodeAppend.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/src/backend/executor/nodeAppend.c b/src/backend/executor/nodeAppend.c index 7a3dd2ee2d0..dcbf4d68aa4 100644 --- a/src/backend/executor/nodeAppend.c +++ b/src/backend/executor/nodeAppend.c @@ -162,7 +162,7 @@ ExecInitAppend(Append *node, EState *estate, int eflags) appendstate->as_whichplan = appendstate->ps.plan->parallel_aware ? INVALID_SUBPLAN_INDEX : 0; - /* If parallel-aware, this will be overridden later. */ + /* For parallel query, this will be overridden later. */ appendstate->choose_next_subplan = choose_next_subplan_locally; return appendstate; @@ -361,14 +361,21 @@ choose_next_subplan_locally(AppendState *node) { int whichplan = node->as_whichplan; - /* We should never see INVALID_SUBPLAN_INDEX in this case. */ - Assert(whichplan >= 0 && whichplan <= node->as_nplans); - if (ScanDirectionIsForward(node->ps.state->es_direction)) { - if (whichplan >= node->as_nplans - 1) - return false; - node->as_whichplan++; + /* + * We won't normally see INVALID_SUBPLAN_INDEX in this case, but we + * might if a plan intended to be run in parallel ends up being run + * serially. + */ + if (whichplan == INVALID_SUBPLAN_INDEX) + node->as_whichplan = 0; + else + { + if (whichplan >= node->as_nplans - 1) + return false; + node->as_whichplan++; + } } else { |