commit

src/backend/distributed/transaction/transaction_recovery.c

@@ -261,11 +261,32 @@ RecoverWorkerTransactions(WorkerNode *workerNode)
 			continue;
 		}
 
-		/* Check if the transaction is created by an outer transaction from a non-main database */
 		bool outerXidIsNull = false;
-		Datum outerXidDatum = heap_getattr(heapTuple,
-										   Anum_pg_dist_transaction_outerxid,
-										   tupleDescriptor, &outerXidIsNull);
+		Datum outerXidDatum = 0;
+
+		HeapTuple outerXidAttTuple =
+			SearchSysCacheCopyAttName(DistTransactionRelationId(), "outer_xid");
+		if (HeapTupleIsValid(outerXidAttTuple))
+		{
+			ReleaseSysCache(outerXidAttTuple);
+
+			/* Check if the transaction is created by an outer transaction from a non-main database */
+			outerXidDatum = heap_getattr(heapTuple,
+										 Anum_pg_dist_transaction_outerxid,
+										 tupleDescriptor, &outerXidIsNull);
+		}
+		else
+		{
+			/*
+			 * Normally we don't try to recover prepared transactions when the
+			 * binary version doesn't match the sql version. However, we skip
+			 * those checks in regression tests by disabling
+			 * citus.enable_version_checks. And when this is the case, while
+			 * the C code looks for "outer_xid" attribute, pg_dist_transaction
+			 * doesn't yet have it.
+			 */
+			Assert(!EnableVersionChecks);
+		}
 
 		TransactionId outerXid = 0;
 		if (!outerXidIsNull)