diff --git a/doc/src/sgml/custom-scan.sgml b/doc/src/sgml/custom-scan.sgml
index 1ca92471245..6159c3a24eb 100644
--- a/doc/src/sgml/custom-scan.sgml
+++ b/doc/src/sgml/custom-scan.sgml
@@ -340,6 +340,19 @@ void (*InitializeWorkerCustomScan) (CustomScanState *node,
+void (*ShutdownCustomScan) (CustomScanState *node);
+
+ Release resources when it is anticipated the node will not be executed
+ to completion. This is not called in all cases; sometimes,
+ EndCustomScan may be called without this function having
+ been called first. Since the DSM segment used by parallel query is
+ destroyed just after this callback is invoked, custom scan providers that
+ wish to take some action before the DSM segment goes away should implement
+ this method.
+
+
+
+
void (*ExplainCustomScan) (CustomScanState *node,
List *ancestors,
ExplainState *es);
diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml
index 0c1db070ed8..dbeaab555db 100644
--- a/doc/src/sgml/fdwhandler.sgml
+++ b/doc/src/sgml/fdwhandler.sgml
@@ -1254,6 +1254,20 @@ InitializeWorkerForeignScan(ForeignScanState *node, shm_toc *toc,
This callback is optional, and needs only be supplied if this
custom path supports parallel execution.
+
+
+
+void
+ShutdownForeignScan(ForeignScanState *node);
+
+ Release resources when it is anticipated the node will not be executed
+ to completion. This is not called in all cases; sometimes,
+ EndForeignScan may be called without this function having
+ been called first. Since the DSM segment used by parallel query is
+ destroyed just after this callback is invoked, foreign data wrappers that
+ wish to take some action before the DSM segment goes away should implement
+ this method.
+
diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c
index 5ccc2e846dc..ef6f35a5a0b 100644
--- a/src/backend/executor/execProcnode.c
+++ b/src/backend/executor/execProcnode.c
@@ -822,6 +822,12 @@ ExecShutdownNode(PlanState *node)
case T_GatherState:
ExecShutdownGather((GatherState *) node);
break;
+ case T_ForeignScanState:
+ ExecShutdownForeignScan((ForeignScanState *) node);
+ break;
+ case T_CustomScanState:
+ ExecShutdownCustomScan((CustomScanState *) node);
+ break;
default:
break;
}
diff --git a/src/backend/executor/nodeCustom.c b/src/backend/executor/nodeCustom.c
index 16343a56df7..d4647482905 100644
--- a/src/backend/executor/nodeCustom.c
+++ b/src/backend/executor/nodeCustom.c
@@ -202,3 +202,12 @@ ExecCustomScanInitializeWorker(CustomScanState *node, shm_toc *toc)
methods->InitializeWorkerCustomScan(node, toc, coordinate);
}
}
+
+void
+ExecShutdownCustomScan(CustomScanState *node)
+{
+ const CustomExecMethods *methods = node->methods;
+
+ if (methods->ShutdownCustomScan)
+ methods->ShutdownCustomScan(node);
+}
diff --git a/src/backend/executor/nodeForeignscan.c b/src/backend/executor/nodeForeignscan.c
index 86a77e356c0..3b6d1390eb4 100644
--- a/src/backend/executor/nodeForeignscan.c
+++ b/src/backend/executor/nodeForeignscan.c
@@ -353,3 +353,19 @@ ExecForeignScanInitializeWorker(ForeignScanState *node, shm_toc *toc)
fdwroutine->InitializeWorkerForeignScan(node, toc, coordinate);
}
}
+
+/* ----------------------------------------------------------------
+ * ExecShutdownForeignScan
+ *
+ * Gives FDW chance to stop asynchronous resource consumption
+ * and release any resources still held.
+ * ----------------------------------------------------------------
+ */
+void
+ExecShutdownForeignScan(ForeignScanState *node)
+{
+ FdwRoutine *fdwroutine = node->fdwroutine;
+
+ if (fdwroutine->ShutdownForeignScan)
+ fdwroutine->ShutdownForeignScan(node);
+}
diff --git a/src/include/executor/nodeCustom.h b/src/include/executor/nodeCustom.h
index 19d5d047b5c..c2f2ca1eede 100644
--- a/src/include/executor/nodeCustom.h
+++ b/src/include/executor/nodeCustom.h
@@ -37,5 +37,6 @@ extern void ExecCustomScanInitializeDSM(CustomScanState *node,
ParallelContext *pcxt);
extern void ExecCustomScanInitializeWorker(CustomScanState *node,
shm_toc *toc);
+extern void ExecShutdownCustomScan(CustomScanState *node);
#endif /* NODECUSTOM_H */
diff --git a/src/include/executor/nodeForeignscan.h b/src/include/executor/nodeForeignscan.h
index f0e942a8bcb..1b167b8143a 100644
--- a/src/include/executor/nodeForeignscan.h
+++ b/src/include/executor/nodeForeignscan.h
@@ -28,5 +28,6 @@ extern void ExecForeignScanInitializeDSM(ForeignScanState *node,
ParallelContext *pcxt);
extern void ExecForeignScanInitializeWorker(ForeignScanState *node,
shm_toc *toc);
+extern void ExecShutdownForeignScan(ForeignScanState *node);
#endif /* NODEFOREIGNSCAN_H */
diff --git a/src/include/foreign/fdwapi.h b/src/include/foreign/fdwapi.h
index 523d4155756..6ca44f734f9 100644
--- a/src/include/foreign/fdwapi.h
+++ b/src/include/foreign/fdwapi.h
@@ -151,6 +151,7 @@ typedef void (*InitializeDSMForeignScan_function) (ForeignScanState *node,
typedef void (*InitializeWorkerForeignScan_function) (ForeignScanState *node,
shm_toc *toc,
void *coordinate);
+typedef void (*ShutdownForeignScan_function) (ForeignScanState *node);
typedef bool (*IsForeignScanParallelSafe_function) (PlannerInfo *root,
RelOptInfo *rel,
RangeTblEntry *rte);
@@ -224,6 +225,7 @@ typedef struct FdwRoutine
EstimateDSMForeignScan_function EstimateDSMForeignScan;
InitializeDSMForeignScan_function InitializeDSMForeignScan;
InitializeWorkerForeignScan_function InitializeWorkerForeignScan;
+ ShutdownForeignScan_function ShutdownForeignScan;
} FdwRoutine;
diff --git a/src/include/nodes/extensible.h b/src/include/nodes/extensible.h
index 7e860b0dca7..0b02cc18e99 100644
--- a/src/include/nodes/extensible.h
+++ b/src/include/nodes/extensible.h
@@ -139,6 +139,7 @@ typedef struct CustomExecMethods
void (*InitializeWorkerCustomScan) (CustomScanState *node,
shm_toc *toc,
void *coordinate);
+ void (*ShutdownCustomScan) (CustomScanState *node);
/* Optional: print additional information in EXPLAIN */
void (*ExplainCustomScan) (CustomScanState *node,