sync-rep-apply-quick-hack.patch

diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c
index 325239d..2e18768 100644
--- a/src/backend/replication/syncrep.c
+++ b/src/backend/replication/syncrep.c
@@ -462,6 +462,11 @@ SyncRepReleaseWaiters(void)
 		walsndctl->lsn[SYNC_REP_WAIT_FLUSH] = MyWalSnd->flush;
 		numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_FLUSH);
 	}
+	if (walsndctl->lsn[SYNC_REP_WAIT_APPLY] < MyWalSnd->apply)
+	{
+		walsndctl->lsn[SYNC_REP_WAIT_APPLY] = MyWalSnd->apply;
+		numflush = SyncRepWakeQueue(false, SYNC_REP_WAIT_APPLY);
+	}
 
 	LWLockRelease(SyncRepLock);
 
@@ -728,6 +733,9 @@ assign_synchronous_commit(int newval, void *extra)
 		case SYNCHRONOUS_COMMIT_REMOTE_FLUSH:
 			SyncRepWaitMode = SYNC_REP_WAIT_FLUSH;
 			break;
+		case SYNCHRONOUS_COMMIT_REMOTE_APPLY:
+			SyncRepWaitMode = SYNC_REP_WAIT_APPLY;
+			break;
 		default:
 			SyncRepWaitMode = SYNC_REP_NO_WAIT;
 			break;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 1b7b914..2673fc0 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -351,6 +351,7 @@ static const struct config_enum_entry constraint_exclusion_options[] = {
 static const struct config_enum_entry synchronous_commit_options[] = {
 	{"local", SYNCHRONOUS_COMMIT_LOCAL_FLUSH, false},
 	{"remote_write", SYNCHRONOUS_COMMIT_REMOTE_WRITE, false},
+	{"apply", SYNCHRONOUS_COMMIT_REMOTE_APPLY, false},
 	{"on", SYNCHRONOUS_COMMIT_ON, false},
 	{"off", SYNCHRONOUS_COMMIT_OFF, false},
 	{"true", SYNCHRONOUS_COMMIT_ON, true},
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index cb1c2db..d8433e2 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -60,7 +60,9 @@ typedef enum
 	SYNCHRONOUS_COMMIT_LOCAL_FLUSH,		/* wait for local flush only */
 	SYNCHRONOUS_COMMIT_REMOTE_WRITE,	/* wait for local flush and remote
 										 * write */
-	SYNCHRONOUS_COMMIT_REMOTE_FLUSH		/* wait for local and remote flush */
+	SYNCHRONOUS_COMMIT_REMOTE_FLUSH,	/* wait for local and remote flush */
+	SYNCHRONOUS_COMMIT_REMOTE_APPLY		/* wait for local flush and remote
+										 * apply */
 }	SyncCommitLevel;
 
 /* Define the default setting for synchonous_commit */
diff --git a/src/include/replication/syncrep.h b/src/include/replication/syncrep.h
index 71e2857..8e0fe00 100644
--- a/src/include/replication/syncrep.h
+++ b/src/include/replication/syncrep.h
@@ -23,8 +23,9 @@
 #define SYNC_REP_NO_WAIT		-1
 #define SYNC_REP_WAIT_WRITE		0
 #define SYNC_REP_WAIT_FLUSH		1
+#define SYNC_REP_WAIT_APPLY		2
 
-#define NUM_SYNC_REP_WAIT_MODE	2
+#define NUM_SYNC_REP_WAIT_MODE	3
 
 /* syncRepState */
 #define SYNC_REP_NOT_WAITING		0