Add special handling for catalog snapshot

knizhnik · knizhnik · commit 8cd3c51b98a0 · 2017-02-09T12:11:18.000+03:00
diff --git a/contrib/mmts/multimaster.c b/contrib/mmts/multimaster.c
@@ -457,7 +457,9 @@ csn_t MtmDistributedTransactionSnapshot(TransactionId xid, int nodeId, nodemask_
 Snapshot MtmGetSnapshot(Snapshot snapshot)
 {
     snapshot = PgGetSnapshotData(snapshot);
-	RecentGlobalDataXmin = RecentGlobalXmin = Mtm->oldestXid;
+	if (snapshot != &CatalogSnapshotData) {
+		RecentGlobalDataXmin = RecentGlobalXmin = Mtm->oldestXid;
+	}
     return snapshot;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -457,7 +457,9 @@ csn_t MtmDistributedTransactionSnapshot(TransactionId xid, int nodeId, nodemask_`
`457`	`457`	`Snapshot MtmGetSnapshot(Snapshot snapshot)`
`458`	`458`	`{`
`459`	`459`	`snapshot = PgGetSnapshotData(snapshot);`
`460`		`- RecentGlobalDataXmin = RecentGlobalXmin = Mtm->oldestXid;`
	`460`	`+ if (snapshot != &CatalogSnapshotData) {`
	`461`	`+ RecentGlobalDataXmin = RecentGlobalXmin = Mtm->oldestXid;`
	`462`	`+ }`
`461`	`463`	`return snapshot;`
`462`	`464`	`}`
`463`	`465`