diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 6f7ee0c947d953d2dd49d2be535b5a0d128d8f02..5adf956f4133e98d836ac295d5e51748f644df05 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1338,7 +1338,8 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
 				 errmsg("out of memory"),
 				 errdetail("Failed while allocating a WAL reading processor.")));
 
-	record = XLogReadRecord(xlogreader, lsn, &errormsg);
+	XLogBeginRead(xlogreader, lsn);
+	record = XLogReadRecord(xlogreader, &errormsg);
 	if (record == NULL)
 		ereport(ERROR,
 				(errcode_for_file_access(),
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 7f4f784c0eb64216397b4c1af8bf3129d07b141f..882d5e8a73fc8e6af7f6d5d36815df48164c5627 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -897,7 +897,7 @@ static void UpdateLastRemovedPtr(char *filename);
 static void ValidateXLOGDirectoryStructure(void);
 static void CleanupBackupHistory(void);
 static void UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force);
-static XLogRecord *ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr,
+static XLogRecord *ReadRecord(XLogReaderState *xlogreader,
 							  int emode, bool fetching_ckpt);
 static void CheckRecoveryConsistency(void);
 static XLogRecord *ReadCheckpointRecord(XLogReaderState *xlogreader,
@@ -4246,17 +4246,17 @@ CleanupBackupHistory(void)
 }
 
 /*
- * Attempt to read an XLOG record.
+ * Attempt to read the next XLOG record.
  *
- * If RecPtr is valid, try to read a record at that position.  Otherwise
- * try to read a record just after the last one previously read.
+ * Before first call, the reader needs to be positioned to the first record
+ * by calling XLogBeginRead().
  *
  * If no valid record is available, returns NULL, or fails if emode is PANIC.
  * (emode must be either PANIC, LOG). In standby mode, retries until a valid
  * record is available.
  */
 static XLogRecord *
-ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
+ReadRecord(XLogReaderState *xlogreader, int emode,
 		   bool fetching_ckpt)
 {
 	XLogRecord *record;
@@ -4265,7 +4265,7 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 	/* Pass through parameters to XLogPageRead */
 	private->fetching_ckpt = fetching_ckpt;
 	private->emode = emode;
-	private->randAccess = (RecPtr != InvalidXLogRecPtr);
+	private->randAccess = (xlogreader->ReadRecPtr != InvalidXLogRecPtr);
 
 	/* This is the first attempt to read this page. */
 	lastSourceFailed = false;
@@ -4274,7 +4274,7 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 	{
 		char	   *errormsg;
 
-		record = XLogReadRecord(xlogreader, RecPtr, &errormsg);
+		record = XLogReadRecord(xlogreader, &errormsg);
 		ReadRecPtr = xlogreader->ReadRecPtr;
 		EndRecPtr = xlogreader->EndRecPtr;
 		if (record == NULL)
@@ -4292,8 +4292,7 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 			 * shouldn't loop anymore in that case.
 			 */
 			if (errormsg)
-				ereport(emode_for_corrupt_record(emode,
-												 RecPtr ? RecPtr : EndRecPtr),
+				ereport(emode_for_corrupt_record(emode, EndRecPtr),
 						(errmsg_internal("%s", errormsg) /* already translated */ ));
 		}
 
@@ -4311,8 +4310,7 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 									   wal_segment_size);
 			XLogFileName(fname, xlogreader->seg.ws_tli, segno,
 						 wal_segment_size);
-			ereport(emode_for_corrupt_record(emode,
-											 RecPtr ? RecPtr : EndRecPtr),
+			ereport(emode_for_corrupt_record(emode, EndRecPtr),
 					(errmsg("unexpected timeline ID %u in log segment %s, offset %u",
 							xlogreader->latestPageTLI,
 							fname,
@@ -6427,7 +6425,8 @@ StartupXLOG(void)
 			 */
 			if (checkPoint.redo < checkPointLoc)
 			{
-				if (!ReadRecord(xlogreader, checkPoint.redo, LOG, false))
+				XLogBeginRead(xlogreader, checkPoint.redo);
+				if (!ReadRecord(xlogreader, LOG, false))
 					ereport(FATAL,
 							(errmsg("could not find redo location referenced by checkpoint record"),
 							 errhint("If you are restoring from a backup, touch \"%s/recovery.signal\" and add required recovery options.\n"
@@ -7034,12 +7033,13 @@ StartupXLOG(void)
 		if (checkPoint.redo < RecPtr)
 		{
 			/* back up to find the record */
-			record = ReadRecord(xlogreader, checkPoint.redo, PANIC, false);
+			XLogBeginRead(xlogreader, checkPoint.redo);
+			record = ReadRecord(xlogreader, PANIC, false);
 		}
 		else
 		{
 			/* just have to read next record after CheckPoint */
-			record = ReadRecord(xlogreader, InvalidXLogRecPtr, LOG, false);
+			record = ReadRecord(xlogreader, LOG, false);
 		}
 
 		if (record != NULL)
@@ -7263,7 +7263,7 @@ StartupXLOG(void)
 				}
 
 				/* Else, try to fetch the next WAL record */
-				record = ReadRecord(xlogreader, InvalidXLogRecPtr, LOG, false);
+				record = ReadRecord(xlogreader, LOG, false);
 			} while (record != NULL);
 
 			/*
@@ -7365,7 +7365,8 @@ StartupXLOG(void)
 	 * Re-fetch the last valid or last applied record, so we can identify the
 	 * exact endpoint of what we consider the valid portion of WAL.
 	 */
-	record = ReadRecord(xlogreader, LastRec, PANIC, false);
+	XLogBeginRead(xlogreader, LastRec);
+	record = ReadRecord(xlogreader, PANIC, false);
 	EndOfLog = EndRecPtr;
 
 	/*
@@ -8094,7 +8095,8 @@ ReadCheckpointRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr,
 		return NULL;
 	}
 
-	record = ReadRecord(xlogreader, RecPtr, LOG, true);
+	XLogBeginRead(xlogreader, RecPtr);
+	record = ReadRecord(xlogreader, LOG, true);
 
 	if (record == NULL)
 	{
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 3aa68127a3ec9258570a48a8bcbdf408e8c5f50c..32f02256edb24069dee9e18e66630293bd03c1cc 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -218,11 +218,34 @@ WALOpenSegmentInit(WALOpenSegment *seg, WALSegmentContext *segcxt,
 		snprintf(segcxt->ws_dir, MAXPGPATH, "%s", waldir);
 }
 
+/*
+ * Begin reading WAL at 'RecPtr'.
+ *
+ * 'RecPtr' should point to the beginnning of a valid WAL record.  Pointing at
+ * the beginning of a page is also OK, if there is a new record right after
+ * the page header, i.e. not a continuation.
+ *
+ * This does not make any attempt to read the WAL yet, and hence cannot fail.
+ * If the starting address is not correct, the first call to XLogReadRecord()
+ * will error out.
+ */
+void
+XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr)
+{
+	Assert(!XLogRecPtrIsInvalid(RecPtr));
+
+	ResetDecoder(state);
+
+	/* Begin at the passed-in record pointer. */
+	state->EndRecPtr = RecPtr;
+	state->ReadRecPtr = InvalidXLogRecPtr;
+}
+
 /*
  * Attempt to read an XLOG record.
  *
- * If RecPtr is valid, try to read a record at that position.  Otherwise
- * try to read a record just after the last one previously read.
+ * XLogBeginRead() or XLogFindNextRecord() must be called before the first call
+ * to XLogReadRecord().
  *
  * If the read_page callback fails to read the requested data, NULL is
  * returned.  The callback is expected to have reported the error; errormsg
@@ -235,8 +258,9 @@ WALOpenSegmentInit(WALOpenSegment *seg, WALSegmentContext *segcxt,
  * valid until the next call to XLogReadRecord.
  */
 XLogRecord *
-XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
+XLogReadRecord(XLogReaderState *state, char **errormsg)
 {
+	XLogRecPtr	RecPtr;
 	XLogRecord *record;
 	XLogRecPtr	targetPagePtr;
 	bool		randAccess;
@@ -260,19 +284,17 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 
 	ResetDecoder(state);
 
-	if (RecPtr == InvalidXLogRecPtr)
-	{
-		/* No explicit start point; read the record after the one we just read */
-		RecPtr = state->EndRecPtr;
+	RecPtr = state->EndRecPtr;
 
-		if (state->ReadRecPtr == InvalidXLogRecPtr)
-			randAccess = true;
+	if (state->ReadRecPtr != InvalidXLogRecPtr)
+	{
+		/* read the record after the one we just read */
 
 		/*
-		 * RecPtr is pointing to end+1 of the previous WAL record.  If we're
-		 * at a page boundary, no more records can fit on the current page. We
-		 * must skip over the page header, but we can't do that until we've
-		 * read in the page, since the header size is variable.
+		 * EndRecPtr is pointing to end+1 of the previous WAL record.  If
+		 * we're at a page boundary, no more records can fit on the current
+		 * page. We must skip over the page header, but we can't do that until
+		 * we've read in the page, since the header size is variable.
 		 */
 	}
 	else
@@ -280,8 +302,8 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 		/*
 		 * Caller supplied a position to start at.
 		 *
-		 * In this case, the passed-in record pointer should already be
-		 * pointing to a valid record starting position.
+		 * In this case, EndRecPtr should already be pointing to a valid
+		 * record starting position.
 		 */
 		Assert(XRecOffIsValid(RecPtr));
 		randAccess = true;
@@ -899,14 +921,17 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 /*
  * Find the first record with an lsn >= RecPtr.
  *
- * Useful for checking whether RecPtr is a valid xlog address for reading, and
- * to find the first valid address after some address when dumping records for
- * debugging purposes.
+ * This is different from XLogBeginRead() in that RecPtr doesn't need to point
+ * to a valid record boundary.  Useful for checking whether RecPtr is a valid
+ * xlog address for reading, and to find the first valid address after some
+ * address when dumping records for debugging purposes.
+ *
+ * This positions the reader, like XLogBeginRead(), so that the next call to
+ * XLogReadRecord() will read the next valid record.
  */
 XLogRecPtr
 XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr)
 {
-	XLogReaderState saved_state = *state;
 	XLogRecPtr	tmpRecPtr;
 	XLogRecPtr	found = InvalidXLogRecPtr;
 	XLogPageHeader header;
@@ -991,27 +1016,23 @@ XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr)
 	 * because either we're at the first record after the beginning of a page
 	 * or we just jumped over the remaining data of a continuation.
 	 */
-	while (XLogReadRecord(state, tmpRecPtr, &errormsg) != NULL)
+	XLogBeginRead(state, tmpRecPtr);
+	while (XLogReadRecord(state, &errormsg) != NULL)
 	{
-		/* continue after the record */
-		tmpRecPtr = InvalidXLogRecPtr;
-
 		/* past the record we've found, break out */
 		if (RecPtr <= state->ReadRecPtr)
 		{
+			/* Rewind the reader to the beginning of the last record. */
 			found = state->ReadRecPtr;
-			goto out;
+			XLogBeginRead(state, found);
+			return found;
 		}
 	}
 
 err:
-out:
-	/* Reset state to what we had before finding the record */
-	state->ReadRecPtr = saved_state.ReadRecPtr;
-	state->EndRecPtr = saved_state.EndRecPtr;
 	XLogReaderInvalReadState(state);
 
-	return found;
+	return InvalidXLogRecPtr;
 }
 
 #endif							/* FRONTEND */
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c
index bdf4389a57c63122431115a1ab648fde164d1659..cf9320061882da79c5e3debb2504b6faaaff0fb0 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -461,11 +461,10 @@ DecodingContextReady(LogicalDecodingContext *ctx)
 void
 DecodingContextFindStartpoint(LogicalDecodingContext *ctx)
 {
-	XLogRecPtr	startptr;
 	ReplicationSlot *slot = ctx->slot;
 
 	/* Initialize from where to start reading WAL. */
-	startptr = slot->data.restart_lsn;
+	XLogBeginRead(ctx->reader, slot->data.restart_lsn);
 
 	elog(DEBUG1, "searching for logical decoding starting point, starting at %X/%X",
 		 (uint32) (slot->data.restart_lsn >> 32),
@@ -478,14 +477,12 @@ DecodingContextFindStartpoint(LogicalDecodingContext *ctx)
 		char	   *err = NULL;
 
 		/* the read_page callback waits for new WAL */
-		record = XLogReadRecord(ctx->reader, startptr, &err);
+		record = XLogReadRecord(ctx->reader, &err);
 		if (err)
 			elog(ERROR, "%s", err);
 		if (!record)
 			elog(ERROR, "no record found"); /* shouldn't happen */
 
-		startptr = InvalidXLogRecPtr;
-
 		LogicalDecodingProcessRecord(ctx, ctx->reader);
 
 		/* only continue till we found a consistent spot */
diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c
index 7693c98949d620981ef320be9d30d3ba1ef846c4..25b89e5616c1e13d456fc8d417db8b74e1a02e0d 100644
--- a/src/backend/replication/logical/logicalfuncs.c
+++ b/src/backend/replication/logical/logicalfuncs.c
@@ -127,7 +127,6 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
 	MemoryContext per_query_ctx;
 	MemoryContext oldcontext;
 	XLogRecPtr	end_of_wal;
-	XLogRecPtr	startptr;
 	LogicalDecodingContext *ctx;
 	ResourceOwner old_resowner = CurrentResourceOwner;
 	ArrayType  *arr;
@@ -269,28 +268,21 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
 		 * xacts that committed after the slot's confirmed_flush can be
 		 * accumulated into reorder buffers.
 		 */
-		startptr = MyReplicationSlot->data.restart_lsn;
+		XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
 
 		/* invalidate non-timetravel entries */
 		InvalidateSystemCaches();
 
 		/* Decode until we run out of records */
-		while ((startptr != InvalidXLogRecPtr && startptr < end_of_wal) ||
-			   (ctx->reader->EndRecPtr != InvalidXLogRecPtr && ctx->reader->EndRecPtr < end_of_wal))
+		while (ctx->reader->EndRecPtr < end_of_wal)
 		{
 			XLogRecord *record;
 			char	   *errm = NULL;
 
-			record = XLogReadRecord(ctx->reader, startptr, &errm);
+			record = XLogReadRecord(ctx->reader, &errm);
 			if (errm)
 				elog(ERROR, "%s", errm);
 
-			/*
-			 * Now that we've set up the xlog reader state, subsequent calls
-			 * pass InvalidXLogRecPtr to say "continue from last record"
-			 */
-			startptr = InvalidXLogRecPtr;
-
 			/*
 			 * The {begin_txn,change,commit_txn}_wrapper callbacks above will
 			 * store the description into our tuplestore.
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index bb69683e2ac955e47c0009a7f7751bc77804f279..7c896946118c58dfd946912e634ea1e9dc806b76 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -391,7 +391,6 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
 {
 	LogicalDecodingContext *ctx;
 	ResourceOwner old_resowner = CurrentResourceOwner;
-	XLogRecPtr	startlsn;
 	XLogRecPtr	retlsn;
 
 	PG_TRY();
@@ -411,7 +410,7 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
 		 * Start reading at the slot's restart_lsn, which we know to point to
 		 * a valid record.
 		 */
-		startlsn = MyReplicationSlot->data.restart_lsn;
+		XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
 
 		/* Initialize our return value in case we don't do anything */
 		retlsn = MyReplicationSlot->data.confirmed_flush;
@@ -420,10 +419,7 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
 		InvalidateSystemCaches();
 
 		/* Decode at least one record, until we run out of records */
-		while ((!XLogRecPtrIsInvalid(startlsn) &&
-				startlsn < moveto) ||
-			   (!XLogRecPtrIsInvalid(ctx->reader->EndRecPtr) &&
-				ctx->reader->EndRecPtr < moveto))
+		while (ctx->reader->EndRecPtr < moveto)
 		{
 			char	   *errm = NULL;
 			XLogRecord *record;
@@ -432,13 +428,10 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
 			 * Read records.  No changes are generated in fast_forward mode,
 			 * but snapbuilder/slot statuses are updated properly.
 			 */
-			record = XLogReadRecord(ctx->reader, startlsn, &errm);
+			record = XLogReadRecord(ctx->reader, &errm);
 			if (errm)
 				elog(ERROR, "%s", errm);
 
-			/* Read sequentially from now on */
-			startlsn = InvalidXLogRecPtr;
-
 			/*
 			 * Process the record.  Storage-level changes are ignored in
 			 * fast_forward mode, but other modules (such as snapbuilder)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 9c063749b62b28f42cf2d59087721e5d6579c272..0c65f1660b2e70b3652a15161ff3757c0796d172 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -191,7 +191,6 @@ static volatile sig_atomic_t got_STOPPING = false;
 static volatile sig_atomic_t replication_active = false;
 
 static LogicalDecodingContext *logical_decoding_ctx = NULL;
-static XLogRecPtr logical_startptr = InvalidXLogRecPtr;
 
 /* A sample associating a WAL location with the time it was written. */
 typedef struct
@@ -1130,9 +1129,9 @@ StartLogicalReplication(StartReplicationCmd *cmd)
 	pq_endmessage(&buf);
 	pq_flush();
 
-
 	/* Start reading WAL from the oldest required WAL. */
-	logical_startptr = MyReplicationSlot->data.restart_lsn;
+	XLogBeginRead(logical_decoding_ctx->reader,
+				  MyReplicationSlot->data.restart_lsn);
 
 	/*
 	 * Report the location after which we'll send out further commits as the
@@ -2791,8 +2790,7 @@ XLogSendLogical(void)
 	 */
 	WalSndCaughtUp = false;
 
-	record = XLogReadRecord(logical_decoding_ctx->reader, logical_startptr, &errm);
-	logical_startptr = InvalidXLogRecPtr;
+	record = XLogReadRecord(logical_decoding_ctx->reader, &errm);
 
 	/* xlog record was invalid */
 	if (errm != NULL)
diff --git a/src/bin/pg_rewind/parsexlog.c b/src/bin/pg_rewind/parsexlog.c
index b6429827cfb58c07e6766e0a3c33fd4580c7932d..eb61cb8803f3ccae67717a5c90476e946b83d307 100644
--- a/src/bin/pg_rewind/parsexlog.c
+++ b/src/bin/pg_rewind/parsexlog.c
@@ -68,15 +68,14 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, int tliIndex,
 	if (xlogreader == NULL)
 		pg_fatal("out of memory");
 
+	XLogBeginRead(xlogreader, startpoint);
 	do
 	{
-		record = XLogReadRecord(xlogreader, startpoint, &errormsg);
+		record = XLogReadRecord(xlogreader, &errormsg);
 
 		if (record == NULL)
 		{
-			XLogRecPtr	errptr;
-
-			errptr = startpoint ? startpoint : xlogreader->EndRecPtr;
+			XLogRecPtr	errptr = xlogreader->EndRecPtr;
 
 			if (errormsg)
 				pg_fatal("could not read WAL record at %X/%X: %s",
@@ -89,8 +88,6 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, int tliIndex,
 
 		extractPageInfo(xlogreader);
 
-		startpoint = InvalidXLogRecPtr; /* continue reading at next record */
-
 	} while (xlogreader->ReadRecPtr != endpoint);
 
 	XLogReaderFree(xlogreader);
@@ -120,7 +117,8 @@ readOneRecord(const char *datadir, XLogRecPtr ptr, int tliIndex)
 	if (xlogreader == NULL)
 		pg_fatal("out of memory");
 
-	record = XLogReadRecord(xlogreader, ptr, &errormsg);
+	XLogBeginRead(xlogreader, ptr);
+	record = XLogReadRecord(xlogreader, &errormsg);
 	if (record == NULL)
 	{
 		if (errormsg)
@@ -182,7 +180,8 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex,
 	{
 		uint8		info;
 
-		record = XLogReadRecord(xlogreader, searchptr, &errormsg);
+		XLogBeginRead(xlogreader, searchptr);
+		record = XLogReadRecord(xlogreader, &errormsg);
 
 		if (record == NULL)
 		{
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 23f3518c2e3eb5a1621d11738feacc2b068b9196..83202b5b876be70cb073126ff00dfaa309508059 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -1053,7 +1053,7 @@ main(int argc, char **argv)
 	for (;;)
 	{
 		/* try to read the next record */
-		record = XLogReadRecord(xlogreader_state, first_record, &errormsg);
+		record = XLogReadRecord(xlogreader_state, &errormsg);
 		if (!record)
 		{
 			if (!config.follow || private.endptr_reached)
@@ -1065,9 +1065,6 @@ main(int argc, char **argv)
 			}
 		}
 
-		/* after reading the first record, continue at next one */
-		first_record = InvalidXLogRecPtr;
-
 		/* apply all specified filters */
 		if (config.filter_by_rmgr != -1 &&
 			config.filter_by_rmgr != record->xl_rmid)
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index f7cc8c4e1dedf61beecc7c4a077e043b504c3221..4582196e1851ad7f5454c901c46e1c434300e277 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -13,7 +13,9 @@
  *		how to use the XLogReader infrastructure.
  *
  *		The basic idea is to allocate an XLogReaderState via
- *		XLogReaderAllocate(), and call XLogReadRecord() until it returns NULL.
+ *		XLogReaderAllocate(), position the reader to the first record with
+ *		XLogBeginRead() or XLogFindNextRecord(), and call XLogReadRecord()
+ *		until it returns NULL.
  *
  *		After reading a record with XLogReadRecord(), it's decomposed into
  *		the per-block and main data parts, and the parts can be accessed
@@ -126,7 +128,8 @@ struct XLogReaderState
 
 	/*
 	 * Start and end point of last record read.  EndRecPtr is also used as the
-	 * position to read next, if XLogReadRecord receives an invalid recptr.
+	 * position to read next.  Calling XLogBeginRead() sets EndRecPtr to the
+	 * starting position and ReadRecPtr to invalid.
 	 */
 	XLogRecPtr	ReadRecPtr;		/* start of last record read */
 	XLogRecPtr	EndRecPtr;		/* end+1 of last record read */
@@ -239,18 +242,20 @@ typedef int (*WALSegmentOpen) (XLogSegNo nextSegNo, WALSegmentContext *segcxt,
 extern void WALOpenSegmentInit(WALOpenSegment *seg, WALSegmentContext *segcxt,
 							   int segsize, const char *waldir);
 
+/* Position the XLogReader to given record */
+extern void XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr);
+#ifdef FRONTEND
+extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr);
+#endif							/* FRONTEND */
+
 /* Read the next XLog record. Returns NULL on end-of-WAL or failure */
 extern struct XLogRecord *XLogReadRecord(XLogReaderState *state,
-										 XLogRecPtr recptr, char **errormsg);
+										 char **errormsg);
 
 /* Validate a page */
 extern bool XLogReaderValidatePageHeader(XLogReaderState *state,
 										 XLogRecPtr recptr, char *phdr);
 
-#ifdef FRONTEND
-extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr);
-#endif							/* FRONTEND */
-
 /*
  * Error information from WALRead that both backend and frontend caller can
  * process.  Currently only errors from pg_pread can be reported.