diff options
Diffstat (limited to 'src/backend/executor/nodeGatherMerge.c')
| -rw-r--r-- | src/backend/executor/nodeGatherMerge.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/src/backend/executor/nodeGatherMerge.c b/src/backend/executor/nodeGatherMerge.c index 2526c584fd0..f50841699c4 100644 --- a/src/backend/executor/nodeGatherMerge.c +++ b/src/backend/executor/nodeGatherMerge.c @@ -327,6 +327,9 @@ ExecShutdownGatherMergeWorkers(GatherMergeState *node) void ExecReScanGatherMerge(GatherMergeState *node) { + GatherMerge *gm = (GatherMerge *) node->ps.plan; + PlanState *outerPlan = outerPlanState(node); + /* * Re-initialize the parallel workers to perform rescan of relation. We * want to gracefully shutdown all the workers so that they should be able @@ -341,7 +344,24 @@ ExecReScanGatherMerge(GatherMergeState *node) if (node->pei) ExecParallelReinitialize(node->pei); - ExecReScan(node->ps.lefttree); + /* + * Set child node's chgParam to tell it that the next scan might deliver a + * different set of rows within the leader process. (The overall rowset + * shouldn't change, but the leader process's subset might; hence nodes + * between here and the parallel table scan node mustn't optimize on the + * assumption of an unchanging rowset.) + */ + if (gm->rescan_param >= 0) + outerPlan->chgParam = bms_add_member(outerPlan->chgParam, + gm->rescan_param); + + + /* + * if chgParam of subnode is not null then plan will be re-scanned by + * first ExecProcNode. + */ + if (outerPlan->chgParam == NULL) + ExecReScan(outerPlan); } /* |