Support global temp tables at replica

Author: knizhnik

src/backend/access/transam/varsup.c

@@ -69,9 +69,10 @@ GetNewTransactionId(bool isSubXact)
 		return FullTransactionIdFromEpochAndXid(0, BootstrapTransactionId);
 	}
 
-	/* safety check, we should never get this far in a HS standby */
+	/* Make it possible to access global temporary tables at standby */
 	if (RecoveryInProgress())
-		elog(ERROR, "cannot assign TransactionIds during recovery");
+		return FullTransactionIdFromEpochAndXid(0, FrozenTransactionId);
+   	    /* elog(ERROR, "cannot assign TransactionIds during recovery"); */
 
 	LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
 

src/backend/access/transam/xact.c

@@ -1206,7 +1206,7 @@ static TransactionId
 RecordTransactionCommit(void)
 {
 	TransactionId xid = GetTopTransactionIdIfAny();
-	bool		markXidCommitted = TransactionIdIsValid(xid);
+	bool		markXidCommitted = TransactionIdIsNormal(xid);
 	TransactionId latestXid = InvalidTransactionId;
 	int			nrels;
 	RelFileNode *rels;
@@ -1624,7 +1624,7 @@ RecordTransactionAbort(bool isSubXact)
 	 * rels to delete (note that this routine is not responsible for actually
 	 * deleting 'em).  We cannot have any child XIDs, either.
 	 */
-	if (!TransactionIdIsValid(xid))
+	if (!TransactionIdIsNormal(xid))
 	{
 		/* Reset XactLastRecEnd until the next transaction writes something */
 		if (!isSubXact)
@@ -2991,6 +2991,9 @@ CommitTransactionCommand(void)
 			 * and then clean up.
 			 */
 		case TBLOCK_ABORT_PENDING:
+			if (GetCurrentTransactionIdIfAny() == FrozenTransactionId)
+				elog(FATAL, "Transaction is aborted at standby");
+
 			AbortTransaction();
 			CleanupTransaction();
 			s->blockState = TBLOCK_DEFAULT;

src/backend/executor/execMain.c

@@ -788,6 +788,9 @@ ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
 		if (isTempNamespace(get_rel_namespace(rte->relid)))
 			continue;
 
+		if (get_rel_persistence(rte->relid) == RELPERSISTENCE_SESSION)
+			continue;
+
 		PreventCommandIfReadOnly(CreateCommandTag((Node *) plannedstmt));
 	}
 

src/backend/optimizer/util/plancat.c

@@ -124,7 +124,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 	relation = table_open(relationObjectId, NoLock);
 
 	/* Temporary and unlogged relations are inaccessible during recovery. */
-	if (!RelationNeedsWAL(relation) && RecoveryInProgress())
+	if (!RelationNeedsWAL(relation) && RecoveryInProgress() && relation->rd_rel->relpersistence != RELPERSISTENCE_SESSION)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot access temporary or unlogged relations during recovery")));