diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 41dae916b4..33ccfc1553 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -26,6 +26,7 @@
 #include "replication/origin.h"
 
 #ifndef FRONTEND
+#include "miscadmin.h"
 #include "utils/memutils.h"
 #endif
 
@@ -1443,3 +1444,37 @@ RestoreBlockImage(XLogReaderState *record, uint8 block_id, char *page)
 
 	return true;
 }
+
+#ifndef FRONTEND
+
+/*
+ * Extract the FullTransactionId from a WAL record.
+ */
+FullTransactionId
+XLogRecGetFullXid(XLogReaderState *record)
+{
+	TransactionId	xid,
+					next_xid;
+	uint32			epoch;
+
+	/*
+	 * This function is only safe during replay, because it depends on the
+	 * replay state.  See AdvanceNextFullTransactionIdPastXid() for more.
+	 */
+	Assert(AmStartupProcess() || !IsUnderPostmaster);
+
+	xid = XLogRecGetXid(record);
+	next_xid = XidFromFullTransactionId(ShmemVariableCache->nextFullXid);
+	epoch = EpochFromFullTransactionId(ShmemVariableCache->nextFullXid);
+
+	/*
+	 * If xid is numerically greater than next_xid, it has to be from the
+	 * last epoch.
+	 */
+	if (unlikely(xid > next_xid))
+		--epoch;
+
+	return FullTransactionIdFromEpochAndXid(epoch, xid);
+};
+
+#endif
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index 04228e2a87..a12c94cba6 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -25,6 +25,10 @@
 #ifndef XLOGREADER_H
 #define XLOGREADER_H
 
+#ifndef FRONTEND
+#include "access/transam.h"
+#endif
+
 #include "access/xlogrecord.h"
 
 typedef struct XLogReaderState XLogReaderState;
@@ -240,6 +244,10 @@ extern bool DecodeXLogRecord(XLogReaderState *state, XLogRecord *record,
 #define XLogRecBlockImageApply(decoder, block_id) \
 	((decoder)->blocks[block_id].apply_image)
 
+#ifndef FRONTEND
+extern FullTransactionId XLogRecGetFullXid(XLogReaderState *record);
+#endif
+
 extern bool RestoreBlockImage(XLogReaderState *recoder, uint8 block_id, char *dst);
 extern char *XLogRecGetBlockData(XLogReaderState *record, uint8 block_id, Size *len);
 extern bool XLogRecGetBlockTag(XLogReaderState *record, uint8 block_id,