should we add a XLogRecPtr/LSN SQL type?

*** a/doc/src/sgml/datatype.sgml
--- b/doc/src/sgml/datatype.sgml
***************
*** 155,160 ****
--- 155,166 ----
        </row>
  
        <row>
+        <entry><type>lsn</type></entry>
+        <entry></entry>
+        <entry>Log Sequence Number</entry>
+       </row>
+ 
+       <row>
         <entry><type>macaddr</type></entry>
         <entry></entry>
         <entry>MAC (Media Access Control) address</entry>
***************
*** 4502,4507 **** SELECT * FROM pg_attribute
--- 4508,4527 ----
     </para>
    </sect1>
  
+   <sect1 id="datatype-lsn">
+    <title><acronym>LSN</> Type</title>
+ 
+    <indexterm zone="datatype-lsn">
+     <primary>LSN</primary>
+    </indexterm>
+ 
+    <para>
+     The <type>lsn</type> data type can be used to store LSN (Log Sequence
+     Number) data which is a pointer to a location in the XLOG. This type is a
+     representation of XLogRecPtr.
+    </para>
+   </sect1>
+ 
    <sect1 id="datatype-pseudo">
     <title>Pseudo-Types</title>
  
*** a/src/backend/utils/adt/Makefile
--- b/src/backend/utils/adt/Makefile
***************
*** 20,26 **** OBJS = acl.o arrayfuncs.o array_selfuncs.o array_typanalyze.o \
  	cash.o char.o date.o datetime.o datum.o domains.o \
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
! 	lockfuncs.o misc.o nabstime.o name.o numeric.o numutils.o \
  	oid.o oracle_compat.o orderedsetaggs.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
--- 20,26 ----
  	cash.o char.o date.o datetime.o datum.o domains.o \
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
! 	lockfuncs.o lsn.o misc.o nabstime.o name.o numeric.o numutils.o \
  	oid.o oracle_compat.o orderedsetaggs.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
*** /dev/null
--- b/src/backend/utils/adt/lsn.c
***************
*** 0 ****
--- 1,180 ----
+ /*-------------------------------------------------------------------------
+  *
+  * lsn.c
+  *	  Internal LSN operations
+  *
+  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * IDENTIFICATION
+  *	  src/backend/utils/adt/lsn.c
+  *
+  *-------------------------------------------------------------------------
+  */
+ #include "postgres.h"
+ 
+ #include "funcapi.h"
+ #include "libpq/pqformat.h"
+ #include "utils/builtins.h"
+ #include "utils/lsn.h"
+ 
+ #define MAXLSNLEN		17
+ #define MAXLSNCOMPONENT	8
+ 
+ /*----------------------------------------------------------
+  * Formatting and conversion routines.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ lsn_in(PG_FUNCTION_ARGS)
+ {
+ 	char	   *str = PG_GETARG_CSTRING(0);
+ 	int			len1, len2;
+ 	uint32		id, off;
+ 	XLogRecPtr	result;
+ 
+ 	/* Sanity check input format. */
+ 	len1 = strspn(str, "0123456789abcdefABCDEF");
+ 	if (len1 < 1 || len1 > MAXLSNCOMPONENT || str[len1] != '/')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for lsn: \"%s\"", str)));
+ 	len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
+ 	if (len2 < 1 || len2 > MAXLSNCOMPONENT || str[len1 + 1 + len2] != '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for lsn: \"%s\"", str)));
+ 
+ 	/* Decode result. */
+ 	id = (uint32) strtoul(str, NULL, 16);
+ 	off = (uint32) strtoul(str + len1 + 1, NULL, 16);
+ 	result = (XLogRecPtr) ((uint64) id << 32) | off;
+ 
+ 	PG_RETURN_LSN(result);
+ }
+ 
+ Datum
+ lsn_out(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr	lsn = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	char		buf[MAXLSNLEN + 1];
+ 	char	   *result;
+ 	uint32		id, off;
+ 
+ 	/* Decode ID and offset */
+ 	id = (uint32) (lsn >> 32);
+ 	off = (uint32) lsn;
+ 
+ 	sprintf(buf, "%X/%X", id, off);
+ 	result = pstrdup(buf);
+ 	PG_RETURN_CSTRING(result);
+ }
+ 
+ Datum
+ lsn_recv(PG_FUNCTION_ARGS)
+ {
+ 	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+ 	XLogRecPtr	result;
+ 
+ 	result = pq_getmsgint64(buf);
+ 	PG_RETURN_LSN(result);
+ }
+ 
+ Datum
+ lsn_send(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	StringInfoData buf;
+ 
+ 	pq_begintypsend(&buf);
+ 	pq_sendint64(&buf, lsn);
+ 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Relational operators for LSNs
+  *---------------------------------------------------------*/
+ 
+ Datum
+ lsn_eq(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 == lsn2);
+ }
+ 
+ Datum
+ lsn_ne(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 != lsn2);
+ }
+ 
+ Datum
+ lsn_lt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 < lsn2);
+ }
+ 
+ Datum
+ lsn_gt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 > lsn2);
+ }
+ 
+ Datum
+ lsn_le(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 <= lsn2);
+ }
+ 
+ Datum
+ lsn_ge(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 >= lsn2);
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Arithmetic operators on LSNs.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ lsn_mi(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 	char		buf[256];
+ 	Datum		result;
+ 
+ 	/* Negative results are not allowed. */
+ 	if (lsn1 < lsn2)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ 				 errmsg("LSN out of range")));
+ 
+ 	/* Convert to numeric. */
+ 	sprintf(buf, UINT64_FORMAT, lsn1 - lsn2);
+ 	result = DirectFunctionCall3(numeric_in,
+ 								 CStringGetDatum(buf),
+ 								 ObjectIdGetDatum(0),
+ 								 Int32GetDatum(-1));
+ 
+ 	return result;
+ }
*** a/src/include/catalog/pg_operator.h
--- b/src/include/catalog/pg_operator.h
***************
*** 1592,1597 **** DESCR("less than or equal");
--- 1592,1613 ----
  DATA(insert OID = 2977 (  ">="	   PGNSP PGUID b f f 2950 2950 16 2976 2974 uuid_ge scalargtsel scalargtjoinsel ));
  DESCR("greater than or equal");
  
+ /* lsn operators */
+ DATA(insert OID = 3222 (  "="	   PGNSP PGUID b f f 3220 3220 16 3222 3223 lsn_eq eqsel eqjoinsel ));
+ DESCR("equal");
+ DATA(insert OID = 3223 (  "<>"	   PGNSP PGUID b f f 3220 3220 16 3223 3222 lsn_ne neqsel neqjoinsel ));
+ DESCR("not equal");
+ DATA(insert OID = 3224 (  "<"	   PGNSP PGUID b f f 3220 3220 16 3225 3227 lsn_lt scalarltsel scalarltjoinsel ));
+ DESCR("less than");
+ DATA(insert OID = 3225 (  ">"	   PGNSP PGUID b f f 3220 3220 16 3224 3226 lsn_gt scalargtsel scalargtjoinsel ));
+ DESCR("greater than");
+ DATA(insert OID = 3226 (  "<="	   PGNSP PGUID b f f 3220 3220 16 3227 3225 lsn_le scalarltsel scalarltjoinsel ));
+ DESCR("less than or equal");
+ DATA(insert OID = 3227 (  ">="	   PGNSP PGUID b f f 3220 3220 16 3226 3224 lsn_ge scalargtsel scalargtjoinsel ));
+ DESCR("greater than or equal");
+ DATA(insert OID = 3228 (  "-"	   PGNSP PGUID b f f 3220 3220 1700    0	0 lsn_mi - - ));
+ DESCR("minus");
+ 
  /* enum operators */
  DATA(insert OID = 3516 (  "="	   PGNSP PGUID b t t 3500 3500 16 3516 3517 enum_eq eqsel eqjoinsel ));
  DESCR("equal");
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 4212,4217 **** DESCR("I/O");
--- 4212,4234 ----
  DATA(insert OID = 2963 (  uuid_hash		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "2950" _null_ _null_ _null_ _null_ uuid_hash _null_ _null_ _null_ ));
  DESCR("hash");
  
+ /* lsn */
+ DATA(insert OID = 3229 (  lsn_in		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2275" _null_ _null_ _null_ _null_ lsn_in _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3230 (  lsn_out		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2275 "3220" _null_ _null_ _null_ _null_ lsn_out _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3231 (  lsn_lt		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_lt _null_ _null_ _null_ ));
+ DATA(insert OID = 3232 (  lsn_le		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_le _null_ _null_ _null_ ));
+ DATA(insert OID = 3233 (  lsn_eq		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_eq _null_ _null_ _null_ ));
+ DATA(insert OID = 3234 (  lsn_ge		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_ge _null_ _null_ _null_ ));
+ DATA(insert OID = 3235 (  lsn_gt		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_gt _null_ _null_ _null_ ));
+ DATA(insert OID = 3236 (  lsn_ne		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_ne _null_ _null_ _null_ ));
+ DATA(insert OID = 3237 (  lsn_mi		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ lsn_mi _null_ _null_ _null_ ));
+ DATA(insert OID = 3238 (  lsn_recv		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2281" _null_ _null_ _null_ _null_ lsn_recv _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3239 (  lsn_send		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 17 "3220" _null_ _null_ _null_ _null_ lsn_send _null_ _null_ _null_ ));
+ DESCR("I/O");
+ 
  /* enum related procs */
  DATA(insert OID = 3504 (  anyenum_in	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3500 "2275" _null_ _null_ _null_ _null_ anyenum_in _null_ _null_ _null_ ));
  DESCR("I/O");
*** a/src/include/catalog/pg_type.h
--- b/src/include/catalog/pg_type.h
***************
*** 577,582 **** DESCR("UUID datatype");
--- 577,587 ----
  #define UUIDOID 2950
  DATA(insert OID = 2951 ( _uuid			PGNSP PGUID -1 f b A f t \054 0 2950 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  
+ /* lsn */
+ DATA(insert OID = 3220 ( lsn			PGNSP PGUID 8 t b U t t \054 0 0 3221 lsn_in lsn_out lsn_recv lsn_send - - - d p f 0 -1 0 0 _null_ _null_ _null_ ));
+ DESCR("LSN datatype");
+ DATA(insert OID = 3221 ( _lsn			PGNSP PGUID -1 f b A f t \054 0 3220 0 array_in array_out array_recv array_send - - array_typanalyze d x f 0 -1 0 0 _null_ _null_ _null_ ));
+ 
  /* text search */
  DATA(insert OID = 3614 ( tsvector		PGNSP PGUID -1 f b U f t \054 0 0 3643 tsvectorin tsvectorout tsvectorrecv tsvectorsend - - ts_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  DESCR("text representation for text search");
*** a/src/include/fmgr.h
--- b/src/include/fmgr.h
***************
*** 230,235 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 230,236 ----
  #define PG_GETARG_CHAR(n)	 DatumGetChar(PG_GETARG_DATUM(n))
  #define PG_GETARG_BOOL(n)	 DatumGetBool(PG_GETARG_DATUM(n))
  #define PG_GETARG_OID(n)	 DatumGetObjectId(PG_GETARG_DATUM(n))
+ #define PG_GETARG_LSN(n)	 DatumGetLogSeqNum(PG_GETARG_DATUM(n))
  #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
  #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
  #define PG_GETARG_NAME(n)	 DatumGetName(PG_GETARG_DATUM(n))
***************
*** 302,307 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 303,309 ----
  #define PG_RETURN_CHAR(x)	 return CharGetDatum(x)
  #define PG_RETURN_BOOL(x)	 return BoolGetDatum(x)
  #define PG_RETURN_OID(x)	 return ObjectIdGetDatum(x)
+ #define PG_RETURN_LSN(x)	 return LogSeqNumGetDatum(x)
  #define PG_RETURN_POINTER(x) return PointerGetDatum(x)
  #define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
  #define PG_RETURN_NAME(x)	 return NameGetDatum(x)
*** a/src/include/postgres.h
--- b/src/include/postgres.h
***************
*** 484,489 **** typedef Datum *DatumPtr;
--- 484,503 ----
  #define ObjectIdGetDatum(X) ((Datum) SET_4_BYTES(X))
  
  /*
+  * DatumGetLogSeqNum
+  *		Returns log sequence number of a datum.
+  */
+ 
+ #define DatumGetLogSeqNum(X) ((XLogRecPtr) GET_8_BYTES(X))
+ 
+ /*
+  * LogSeqNumGetDatum
+  *		Returns datum representation for a log sequence number.
+  */
+ 
+ #define LogSeqNumGetDatum(X) ((Datum) SET_8_BYTES(X))
+ 
+ /*
   * DatumGetTransactionId
   *		Returns transaction identifier value of a datum.
   */
*** /dev/null
--- b/src/include/utils/lsn.h
***************
*** 0 ****
--- 1,33 ----
+ /*-------------------------------------------------------------------------
+  *
+  * lsn.h
+  *		Declarations for operations on log sequence numbers (LSNs).
+  *
+  *
+  * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * src/include/utils/lsn.h
+  *
+  *-------------------------------------------------------------------------
+  */
+ #ifndef LSN_H
+ #define LSN_H
+ 
+ #include "fmgr.h"
+ 
+ extern Datum lsn_in(PG_FUNCTION_ARGS);
+ extern Datum lsn_out(PG_FUNCTION_ARGS);
+ extern Datum lsn_recv(PG_FUNCTION_ARGS);
+ extern Datum lsn_send(PG_FUNCTION_ARGS);
+ 
+ extern Datum lsn_eq(PG_FUNCTION_ARGS);
+ extern Datum lsn_ne(PG_FUNCTION_ARGS);
+ extern Datum lsn_lt(PG_FUNCTION_ARGS);
+ extern Datum lsn_gt(PG_FUNCTION_ARGS);
+ extern Datum lsn_le(PG_FUNCTION_ARGS);
+ extern Datum lsn_ge(PG_FUNCTION_ARGS);
+ 
+ extern Datum lsn_mi(PG_FUNCTION_ARGS);
+ 
+ #endif   /* LSN_H */
*** /dev/null
--- b/src/test/regress/expected/lsn.out
***************
*** 0 ****
--- 1,62 ----
+ --
+ -- LSN
+ --
+ CREATE TABLE LSN_TBL (f1 lsn);
+ -- Largest and smallest input
+ INSERT INTO LSN_TBL VALUES ('0/0');
+ INSERT INTO LSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ -- Incorrect input
+ INSERT INTO LSN_TBL VALUES ('G/0');
+ ERROR:  invalid input syntax for lsn: "G/0"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('G/0');
+                                     ^
+ INSERT INTO LSN_TBL VALUES ('-1/0');
+ ERROR:  invalid input syntax for lsn: "-1/0"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('-1/0');
+                                     ^
+ INSERT INTO LSN_TBL VALUES (' 0/12345678');
+ ERROR:  invalid input syntax for lsn: " 0/12345678"
+ LINE 1: INSERT INTO LSN_TBL VALUES (' 0/12345678');
+                                     ^
+ INSERT INTO LSN_TBL VALUES ('ABCD/');
+ ERROR:  invalid input syntax for lsn: "ABCD/"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('ABCD/');
+                                     ^
+ INSERT INTO LSN_TBL VALUES ('/ABCD');
+ ERROR:  invalid input syntax for lsn: "/ABCD"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('/ABCD');
+                                     ^
+ DROP TABLE LSN_TBL;
+ -- Operators
+ SELECT lsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+  lsn_eq 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+  lsn_ne 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+  lsn_lt 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+  lsn_gt 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ ERROR:  LSN out of range
+ SELECT lsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct
+  lsn_mi 
+ --------
+       1
+ (1 row)
+ 
*** a/src/test/regress/parallel_schedule
--- b/src/test/regress/parallel_schedule
***************
*** 13,19 **** test: tablespace
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes
  
  # Depends on things setup during char, varchar and text
  test: strings
--- 13,19 ----
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes lsn
  
  # Depends on things setup during char, varchar and text
  test: strings
*** a/src/test/regress/serial_schedule
--- b/src/test/regress/serial_schedule
***************
*** 19,24 **** test: uuid
--- 19,25 ----
  test: enum
  test: money
  test: rangetypes
+ test: lsn
  test: strings
  test: numerology
  test: point
*** /dev/null
--- b/src/test/regress/sql/lsn.sql
***************
*** 0 ****
--- 1,25 ----
+ --
+ -- LSN
+ --
+ 
+ CREATE TABLE LSN_TBL (f1 lsn);
+ 
+ -- Largest and smallest input
+ INSERT INTO LSN_TBL VALUES ('0/0');
+ INSERT INTO LSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ 
+ -- Incorrect input
+ INSERT INTO LSN_TBL VALUES ('G/0');
+ INSERT INTO LSN_TBL VALUES ('-1/0');
+ INSERT INTO LSN_TBL VALUES (' 0/12345678');
+ INSERT INTO LSN_TBL VALUES ('ABCD/');
+ INSERT INTO LSN_TBL VALUES ('/ABCD');
+ DROP TABLE LSN_TBL;
+ 
+ -- Operators
+ SELECT lsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+ SELECT lsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT lsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+ SELECT lsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT lsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ SELECT lsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct

*** a/doc/src/sgml/datatype.sgml
--- b/doc/src/sgml/datatype.sgml
***************
*** 155,160 ****
--- 155,166 ----
        </row>
  
        <row>
+        <entry><type>lsn</type></entry>
+        <entry></entry>
+        <entry>Log Sequence Number</entry>
+       </row>
+ 
+       <row>
         <entry><type>macaddr</type></entry>
         <entry></entry>
         <entry>MAC (Media Access Control) address</entry>
***************
*** 4502,4507 **** SELECT * FROM pg_attribute
--- 4508,4527 ----
     </para>
    </sect1>
  
+   <sect1 id="datatype-lsn">
+    <title><acronym>LSN</> Type</title>
+ 
+    <indexterm zone="datatype-lsn">
+     <primary>LSN</primary>
+    </indexterm>
+ 
+    <para>
+     The <type>lsn</type> data type can be used to store LSN (Log Sequence
+     Number) data which is a pointer to a location in the XLOG. This type is a
+     representation of XLogRecPtr.
+    </para>
+   </sect1>
+ 
    <sect1 id="datatype-pseudo">
     <title>Pseudo-Types</title>
  
*** a/src/backend/utils/adt/Makefile
--- b/src/backend/utils/adt/Makefile
***************
*** 20,26 **** OBJS = acl.o arrayfuncs.o array_selfuncs.o array_typanalyze.o \
  	cash.o char.o date.o datetime.o datum.o domains.o \
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
! 	lockfuncs.o misc.o nabstime.o name.o numeric.o numutils.o \
  	oid.o oracle_compat.o orderedsetaggs.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
--- 20,26 ----
  	cash.o char.o date.o datetime.o datum.o domains.o \
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
! 	lockfuncs.o lsn.o misc.o nabstime.o name.o numeric.o numutils.o \
  	oid.o oracle_compat.o orderedsetaggs.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
*** /dev/null
--- b/src/backend/utils/adt/lsn.c
***************
*** 0 ****
--- 1,180 ----
+ /*-------------------------------------------------------------------------
+  *
+  * lsn.c
+  *	  Internal LSN operations
+  *
+  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * IDENTIFICATION
+  *	  src/backend/utils/adt/lsn.c
+  *
+  *-------------------------------------------------------------------------
+  */
+ #include "postgres.h"
+ 
+ #include "funcapi.h"
+ #include "libpq/pqformat.h"
+ #include "utils/builtins.h"
+ #include "utils/lsn.h"
+ 
+ #define MAXLSNLEN		17
+ #define MAXLSNCOMPONENT	8
+ 
+ /*----------------------------------------------------------
+  * Formatting and conversion routines.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ lsn_in(PG_FUNCTION_ARGS)
+ {
+ 	char	   *str = PG_GETARG_CSTRING(0);
+ 	int			len1, len2;
+ 	uint32		id, off;
+ 	XLogRecPtr	result;
+ 
+ 	/* Sanity check input format. */
+ 	len1 = strspn(str, "0123456789abcdefABCDEF");
+ 	if (len1 < 1 || len1 > MAXLSNCOMPONENT || str[len1] != '/')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ 	len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
+ 	if (len2 < 1 || len2 > MAXLSNCOMPONENT || str[len1 + 1 + len2] != '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ 
+ 	/* Decode result. */
+ 	id = (uint32) strtoul(str, NULL, 16);
+ 	off = (uint32) strtoul(str + len1 + 1, NULL, 16);
+ 	result = (XLogRecPtr) ((uint64) id << 32) | off;
+ 
+ 	PG_RETURN_LSN(result);
+ }
+ 
+ Datum
+ lsn_out(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr	lsn = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	char		buf[MAXLSNLEN + 1];
+ 	char	   *result;
+ 	uint32		id, off;
+ 
+ 	/* Decode ID and offset */
+ 	id = (uint32) (lsn >> 32);
+ 	off = (uint32) lsn;
+ 
+ 	sprintf(buf, "%X/%X", id, off);
+ 	result = pstrdup(buf);
+ 	PG_RETURN_CSTRING(result);
+ }
+ 
+ Datum
+ lsn_recv(PG_FUNCTION_ARGS)
+ {
+ 	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+ 	XLogRecPtr	result;
+ 
+ 	result = pq_getmsgint64(buf);
+ 	PG_RETURN_LSN(result);
+ }
+ 
+ Datum
+ lsn_send(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	StringInfoData buf;
+ 
+ 	pq_begintypsend(&buf);
+ 	pq_sendint64(&buf, lsn);
+ 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Relational operators for LSNs
+  *---------------------------------------------------------*/
+ 
+ Datum
+ lsn_eq(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 == lsn2);
+ }
+ 
+ Datum
+ lsn_ne(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 != lsn2);
+ }
+ 
+ Datum
+ lsn_lt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 < lsn2);
+ }
+ 
+ Datum
+ lsn_gt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 > lsn2);
+ }
+ 
+ Datum
+ lsn_le(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 <= lsn2);
+ }
+ 
+ Datum
+ lsn_ge(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 >= lsn2);
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Arithmetic operators on LSNs.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ lsn_mi(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_LSN(1);
+ 	char		buf[256];
+ 	Datum		result;
+ 
+ 	/* Negative results are not allowed. */
+ 	if (lsn1 < lsn2)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ 				 errmsg("LSN out of range")));
+ 
+ 	/* Convert to numeric. */
+ 	sprintf(buf, UINT64_FORMAT, lsn1 - lsn2);
+ 	result = DirectFunctionCall3(numeric_in,
+ 								 CStringGetDatum(buf),
+ 								 ObjectIdGetDatum(0),
+ 								 Int32GetDatum(-1));
+ 
+ 	return result;
+ }
*** a/src/include/catalog/pg_operator.h
--- b/src/include/catalog/pg_operator.h
***************
*** 1592,1597 **** DESCR("less than or equal");
--- 1592,1613 ----
  DATA(insert OID = 2977 (  ">="	   PGNSP PGUID b f f 2950 2950 16 2976 2974 uuid_ge scalargtsel scalargtjoinsel ));
  DESCR("greater than or equal");
  
+ /* lsn operators */
+ DATA(insert OID = 3222 (  "="	   PGNSP PGUID b f f 3220 3220 16 3222 3223 lsn_eq eqsel eqjoinsel ));
+ DESCR("equal");
+ DATA(insert OID = 3223 (  "<>"	   PGNSP PGUID b f f 3220 3220 16 3223 3222 lsn_ne neqsel neqjoinsel ));
+ DESCR("not equal");
+ DATA(insert OID = 3224 (  "<"	   PGNSP PGUID b f f 3220 3220 16 3225 3227 lsn_lt scalarltsel scalarltjoinsel ));
+ DESCR("less than");
+ DATA(insert OID = 3225 (  ">"	   PGNSP PGUID b f f 3220 3220 16 3224 3226 lsn_gt scalargtsel scalargtjoinsel ));
+ DESCR("greater than");
+ DATA(insert OID = 3226 (  "<="	   PGNSP PGUID b f f 3220 3220 16 3227 3225 lsn_le scalarltsel scalarltjoinsel ));
+ DESCR("less than or equal");
+ DATA(insert OID = 3227 (  ">="	   PGNSP PGUID b f f 3220 3220 16 3226 3224 lsn_ge scalargtsel scalargtjoinsel ));
+ DESCR("greater than or equal");
+ DATA(insert OID = 3228 (  "-"	   PGNSP PGUID b f f 3220 3220 1700    0	0 lsn_mi - - ));
+ DESCR("minus");
+ 
  /* enum operators */
  DATA(insert OID = 3516 (  "="	   PGNSP PGUID b t t 3500 3500 16 3516 3517 enum_eq eqsel eqjoinsel ));
  DESCR("equal");
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 4212,4217 **** DESCR("I/O");
--- 4212,4234 ----
  DATA(insert OID = 2963 (  uuid_hash		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "2950" _null_ _null_ _null_ _null_ uuid_hash _null_ _null_ _null_ ));
  DESCR("hash");
  
+ /* lsn */
+ DATA(insert OID = 3229 (  lsn_in		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2275" _null_ _null_ _null_ _null_ lsn_in _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3230 (  lsn_out		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2275 "3220" _null_ _null_ _null_ _null_ lsn_out _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3231 (  lsn_lt		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_lt _null_ _null_ _null_ ));
+ DATA(insert OID = 3232 (  lsn_le		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_le _null_ _null_ _null_ ));
+ DATA(insert OID = 3233 (  lsn_eq		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_eq _null_ _null_ _null_ ));
+ DATA(insert OID = 3234 (  lsn_ge		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_ge _null_ _null_ _null_ ));
+ DATA(insert OID = 3235 (  lsn_gt		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_gt _null_ _null_ _null_ ));
+ DATA(insert OID = 3236 (  lsn_ne		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ lsn_ne _null_ _null_ _null_ ));
+ DATA(insert OID = 3237 (  lsn_mi		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ lsn_mi _null_ _null_ _null_ ));
+ DATA(insert OID = 3238 (  lsn_recv		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2281" _null_ _null_ _null_ _null_ lsn_recv _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3239 (  lsn_send		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 17 "3220" _null_ _null_ _null_ _null_ lsn_send _null_ _null_ _null_ ));
+ DESCR("I/O");
+ 
  /* enum related procs */
  DATA(insert OID = 3504 (  anyenum_in	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3500 "2275" _null_ _null_ _null_ _null_ anyenum_in _null_ _null_ _null_ ));
  DESCR("I/O");
*** a/src/include/catalog/pg_type.h
--- b/src/include/catalog/pg_type.h
***************
*** 577,582 **** DESCR("UUID datatype");
--- 577,587 ----
  #define UUIDOID 2950
  DATA(insert OID = 2951 ( _uuid			PGNSP PGUID -1 f b A f t \054 0 2950 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  
+ /* lsn */
+ DATA(insert OID = 3220 ( lsn			PGNSP PGUID 8 t b U t t \054 0 0 3221 lsn_in lsn_out lsn_recv lsn_send - - - d p f 0 -1 0 0 _null_ _null_ _null_ ));
+ DESCR("LSN datatype");
+ DATA(insert OID = 3221 ( _lsn			PGNSP PGUID -1 f b A f t \054 0 3220 0 array_in array_out array_recv array_send - - array_typanalyze d x f 0 -1 0 0 _null_ _null_ _null_ ));
+ 
  /* text search */
  DATA(insert OID = 3614 ( tsvector		PGNSP PGUID -1 f b U f t \054 0 0 3643 tsvectorin tsvectorout tsvectorrecv tsvectorsend - - ts_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  DESCR("text representation for text search");
*** a/src/include/fmgr.h
--- b/src/include/fmgr.h
***************
*** 230,235 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 230,236 ----
  #define PG_GETARG_CHAR(n)	 DatumGetChar(PG_GETARG_DATUM(n))
  #define PG_GETARG_BOOL(n)	 DatumGetBool(PG_GETARG_DATUM(n))
  #define PG_GETARG_OID(n)	 DatumGetObjectId(PG_GETARG_DATUM(n))
+ #define PG_GETARG_LSN(n)	 DatumGetLogSeqNum(PG_GETARG_DATUM(n))
  #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
  #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
  #define PG_GETARG_NAME(n)	 DatumGetName(PG_GETARG_DATUM(n))
***************
*** 302,307 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 303,309 ----
  #define PG_RETURN_CHAR(x)	 return CharGetDatum(x)
  #define PG_RETURN_BOOL(x)	 return BoolGetDatum(x)
  #define PG_RETURN_OID(x)	 return ObjectIdGetDatum(x)
+ #define PG_RETURN_LSN(x)	 return LogSeqNumGetDatum(x)
  #define PG_RETURN_POINTER(x) return PointerGetDatum(x)
  #define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
  #define PG_RETURN_NAME(x)	 return NameGetDatum(x)
*** a/src/include/postgres.h
--- b/src/include/postgres.h
***************
*** 484,489 **** typedef Datum *DatumPtr;
--- 484,503 ----
  #define ObjectIdGetDatum(X) ((Datum) SET_4_BYTES(X))
  
  /*
+  * DatumGetLogSeqNum
+  *		Returns log sequence number of a datum.
+  */
+ 
+ #define DatumGetLogSeqNum(X) ((XLogRecPtr) GET_8_BYTES(X))
+ 
+ /*
+  * LogSeqNumGetDatum
+  *		Returns datum representation for a log sequence number.
+  */
+ 
+ #define LogSeqNumGetDatum(X) ((Datum) SET_8_BYTES(X))
+ 
+ /*
   * DatumGetTransactionId
   *		Returns transaction identifier value of a datum.
   */
*** /dev/null
--- b/src/include/utils/lsn.h
***************
*** 0 ****
--- 1,33 ----
+ /*-------------------------------------------------------------------------
+  *
+  * lsn.h
+  *		Declarations for operations on log sequence numbers (LSNs).
+  *
+  *
+  * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * src/include/utils/lsn.h
+  *
+  *-------------------------------------------------------------------------
+  */
+ #ifndef LSN_H
+ #define LSN_H
+ 
+ #include "fmgr.h"
+ 
+ extern Datum lsn_in(PG_FUNCTION_ARGS);
+ extern Datum lsn_out(PG_FUNCTION_ARGS);
+ extern Datum lsn_recv(PG_FUNCTION_ARGS);
+ extern Datum lsn_send(PG_FUNCTION_ARGS);
+ 
+ extern Datum lsn_eq(PG_FUNCTION_ARGS);
+ extern Datum lsn_ne(PG_FUNCTION_ARGS);
+ extern Datum lsn_lt(PG_FUNCTION_ARGS);
+ extern Datum lsn_gt(PG_FUNCTION_ARGS);
+ extern Datum lsn_le(PG_FUNCTION_ARGS);
+ extern Datum lsn_ge(PG_FUNCTION_ARGS);
+ 
+ extern Datum lsn_mi(PG_FUNCTION_ARGS);
+ 
+ #endif   /* LSN_H */
*** /dev/null
--- b/src/test/regress/expected/lsn.out
***************
*** 0 ****
--- 1,62 ----
+ --
+ -- LSN
+ --
+ CREATE TABLE LSN_TBL (f1 lsn);
+ -- Largest and smallest input
+ INSERT INTO LSN_TBL VALUES ('0/0');
+ INSERT INTO LSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ -- Incorrect input
+ INSERT INTO LSN_TBL VALUES ('G/0');
+ ERROR:  invalid input syntax for lsn: "G/0"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('G/0');
+                                     ^
+ INSERT INTO LSN_TBL VALUES ('-1/0');
+ ERROR:  invalid input syntax for lsn: "-1/0"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('-1/0');
+                                     ^
+ INSERT INTO LSN_TBL VALUES (' 0/12345678');
+ ERROR:  invalid input syntax for lsn: " 0/12345678"
+ LINE 1: INSERT INTO LSN_TBL VALUES (' 0/12345678');
+                                     ^
+ INSERT INTO LSN_TBL VALUES ('ABCD/');
+ ERROR:  invalid input syntax for lsn: "ABCD/"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('ABCD/');
+                                     ^
+ INSERT INTO LSN_TBL VALUES ('/ABCD');
+ ERROR:  invalid input syntax for lsn: "/ABCD"
+ LINE 1: INSERT INTO LSN_TBL VALUES ('/ABCD');
+                                     ^
+ DROP TABLE LSN_TBL;
+ -- Operators
+ SELECT lsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+  lsn_eq 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+  lsn_ne 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+  lsn_lt 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+  lsn_gt 
+ --------
+  t
+ (1 row)
+ 
+ SELECT lsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ ERROR:  LSN out of range
+ SELECT lsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct
+  lsn_mi 
+ --------
+       1
+ (1 row)
+ 
*** a/src/test/regress/parallel_schedule
--- b/src/test/regress/parallel_schedule
***************
*** 13,19 **** test: tablespace
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes
  
  # Depends on things setup during char, varchar and text
  test: strings
--- 13,19 ----
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes lsn
  
  # Depends on things setup during char, varchar and text
  test: strings
*** a/src/test/regress/serial_schedule
--- b/src/test/regress/serial_schedule
***************
*** 19,24 **** test: uuid
--- 19,25 ----
  test: enum
  test: money
  test: rangetypes
+ test: lsn
  test: strings
  test: numerology
  test: point
*** /dev/null
--- b/src/test/regress/sql/lsn.sql
***************
*** 0 ****
--- 1,25 ----
+ --
+ -- LSN
+ --
+ 
+ CREATE TABLE LSN_TBL (f1 lsn);
+ 
+ -- Largest and smallest input
+ INSERT INTO LSN_TBL VALUES ('0/0');
+ INSERT INTO LSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ 
+ -- Incorrect input
+ INSERT INTO LSN_TBL VALUES ('G/0');
+ INSERT INTO LSN_TBL VALUES ('-1/0');
+ INSERT INTO LSN_TBL VALUES (' 0/12345678');
+ INSERT INTO LSN_TBL VALUES ('ABCD/');
+ INSERT INTO LSN_TBL VALUES ('/ABCD');
+ DROP TABLE LSN_TBL;
+ 
+ -- Operators
+ SELECT lsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+ SELECT lsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT lsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+ SELECT lsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT lsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ SELECT lsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct

*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 15884,15918 **** SELECT set_config('log_statement_stats', 'off', false);
         <entry>
          <literal><function>pg_create_restore_point(<parameter>name</> <type>text</>)</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Create a named point for performing restore (restricted to superusers)</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_current_xlog_insert_location()</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Get current transaction log insert location</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_current_xlog_location()</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Get current transaction log write location</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_start_backup(<parameter>label</> <type>text</> <optional>, <parameter>fast</> <type>boolean</> </optional>)</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Prepare for performing on-line backup (restricted to superusers or replication roles)</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_stop_backup()</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Finish performing on-line backup (restricted to superusers or replication roles)</entry>
        </row>
        <row>
--- 15884,15918 ----
         <entry>
          <literal><function>pg_create_restore_point(<parameter>name</> <type>text</>)</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Create a named point for performing restore (restricted to superusers)</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_current_xlog_insert_location()</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Get current transaction log insert location</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_current_xlog_location()</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Get current transaction log write location</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_start_backup(<parameter>label</> <type>text</> <optional>, <parameter>fast</> <type>boolean</> </optional>)</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Prepare for performing on-line backup (restricted to superusers or replication roles)</entry>
        </row>
        <row>
         <entry>
          <literal><function>pg_stop_backup()</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Finish performing on-line backup (restricted to superusers or replication roles)</entry>
        </row>
        <row>
***************
*** 15933,15958 **** SELECT set_config('log_statement_stats', 'off', false);
         <entry>
          <literal><function>pg_switch_xlog()</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Force switch to a new transaction log file (restricted to superusers)</entry>
        </row>
        <row>
         <entry>
!         <literal><function>pg_xlogfile_name(<parameter>location</> <type>text</>)</function></literal>
          </entry>
         <entry><type>text</type></entry>
         <entry>Convert transaction log location string to file name</entry>
        </row>
        <row>
         <entry>
!         <literal><function>pg_xlogfile_name_offset(<parameter>location</> <type>text</>)</function></literal>
          </entry>
         <entry><type>text</>, <type>integer</></entry>
         <entry>Convert transaction log location string to file name and decimal byte offset within file</entry>
        </row>
        <row>
         <entry>
!         <literal><function>pg_xlog_location_diff(<parameter>location</> <type>text</>, <parameter>location</> <type>text</>)</function></literal>
         </entry>
         <entry><type>numeric</></entry>
         <entry>Calculate the difference between two transaction log locations</entry>
--- 15933,15958 ----
         <entry>
          <literal><function>pg_switch_xlog()</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Force switch to a new transaction log file (restricted to superusers)</entry>
        </row>
        <row>
         <entry>
!         <literal><function>pg_xlogfile_name(<parameter>location</> <type>lsn</>)</function></literal>
          </entry>
         <entry><type>text</type></entry>
         <entry>Convert transaction log location string to file name</entry>
        </row>
        <row>
         <entry>
!         <literal><function>pg_xlogfile_name_offset(<parameter>location</> <type>lsn</>)</function></literal>
          </entry>
         <entry><type>text</>, <type>integer</></entry>
         <entry>Convert transaction log location string to file name and decimal byte offset within file</entry>
        </row>
        <row>
         <entry>
!         <literal><function>pg_xlog_location_diff(<parameter>location</> <type>lsn</>, <parameter>location</> <type>lsn</>)</function></literal>
         </entry>
         <entry><type>numeric</></entry>
         <entry>Calculate the difference between two transaction log locations</entry>
***************
*** 16107,16113 **** postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         <entry>
          <literal><function>pg_last_xlog_receive_location()</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Get last transaction log location received and synced to disk by
          streaming replication. While streaming replication is in progress
          this will increase monotonically. If recovery has completed this will
--- 16107,16113 ----
         <entry>
          <literal><function>pg_last_xlog_receive_location()</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Get last transaction log location received and synced to disk by
          streaming replication. While streaming replication is in progress
          this will increase monotonically. If recovery has completed this will
***************
*** 16121,16127 **** postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         <entry>
          <literal><function>pg_last_xlog_replay_location()</function></literal>
          </entry>
!        <entry><type>text</type></entry>
         <entry>Get last transaction log location replayed during recovery.
          If recovery is still in progress this will increase monotonically.
          If recovery has completed then this value will remain static at
--- 16121,16127 ----
         <entry>
          <literal><function>pg_last_xlog_replay_location()</function></literal>
          </entry>
!        <entry><type>lsn</type></entry>
         <entry>Get last transaction log location replayed during recovery.
          If recovery is still in progress this will increase monotonically.
          If recovery has completed then this value will remain static at
***************
*** 16335,16341 **** postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
          <literal><function>pg_create_physical_replication_slot(<parameter>slotname</parameter> <type>text</type>, <parameter>plugin</parameter> <type>text</type>)</function></literal>
         </entry>
         <entry>
!         (<parameter>slotname</parameter> <type>text</type>, <parameter>xlog_position</parameter> <type>text</type>)
         </entry>
         <entry>
          Creates a new physical replication slot named
--- 16335,16341 ----
          <literal><function>pg_create_physical_replication_slot(<parameter>slotname</parameter> <type>text</type>, <parameter>plugin</parameter> <type>text</type>)</function></literal>
         </entry>
         <entry>
!         (<parameter>slotname</parameter> <type>text</type>, <parameter>xlog_position</parameter> <type>lsn</type>)
         </entry>
         <entry>
          Creates a new physical replication slot named
*** a/src/backend/access/transam/xlogfuncs.c
--- b/src/backend/access/transam/xlogfuncs.c
***************
*** 33,40 ****
  #include "utils/timestamp.h"
  #include "storage/fd.h"
  
- static void validate_xlog_location(char *str);
- 
  
  /*
   * pg_start_backup: set up for taking an on-line backup dump
--- 33,38 ----
*** a/src/backend/catalog/system_views.sql
--- b/src/backend/catalog/system_views.sql
***************
*** 810,816 **** COMMENT ON FUNCTION ts_debug(text) IS
  
  CREATE OR REPLACE FUNCTION
    pg_start_backup(label text, fast boolean DEFAULT false)
!   RETURNS text STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
  
  CREATE OR REPLACE FUNCTION
    json_populate_record(base anyelement, from_json json, use_json_as_text boolean DEFAULT false)
--- 810,816 ----
  
  CREATE OR REPLACE FUNCTION
    pg_start_backup(label text, fast boolean DEFAULT false)
!   RETURNS lsn STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
  
  CREATE OR REPLACE FUNCTION
    json_populate_record(base anyelement, from_json json, use_json_as_text boolean DEFAULT false)
*** a/src/backend/replication/slotfuncs.c
--- b/src/backend/replication/slotfuncs.c
***************
*** 141,148 **** pg_get_replication_slots(PG_FUNCTION_ARGS)
  		bool		active;
  		Oid			database;
  		const char *slot_name;
- 
- 		char		restart_lsn_s[MAXFNAMELEN];
  		int			i;
  
  		SpinLockAcquire(&slot->mutex);
--- 141,146 ----
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 2971,2998 **** DATA(insert OID = 2171 ( pg_cancel_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v
  DESCR("cancel a server process' current query");
  DATA(insert OID = 2096 ( pg_terminate_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 16 "23" _null_ _null_ _null_ _null_ pg_terminate_backend _null_ _null_ _null_ ));
  DESCR("terminate a server process");
! DATA(insert OID = 2172 ( pg_start_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 25 "25 16" _null_ _null_ _null_ _null_ pg_start_backup _null_ _null_ _null_ ));
  DESCR("prepare for taking an online backup");
! DATA(insert OID = 2173 ( pg_stop_backup			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_stop_backup _null_ _null_ _null_ ));
  DESCR("finish taking an online backup");
  DATA(insert OID = 3813 ( pg_is_in_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_backup _null_ _null_ _null_ ));
  DESCR("true if server is in online backup");
  DATA(insert OID = 3814 ( pg_backup_start_time		PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_ pg_backup_start_time _null_ _null_ _null_ ));
  DESCR("start time of an online backup");
! DATA(insert OID = 2848 ( pg_switch_xlog			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_switch_xlog _null_ _null_ _null_ ));
  DESCR("switch to new xlog file");
! DATA(insert OID = 3098 ( pg_create_restore_point	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 25 "25" _null_ _null_ _null_ _null_ pg_create_restore_point _null_ _null_ _null_ ));
  DESCR("create a named restore point");
! DATA(insert OID = 2849 ( pg_current_xlog_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_current_xlog_location _null_ _null_ _null_ ));
  DESCR("current xlog write location");
! DATA(insert OID = 2852 ( pg_current_xlog_insert_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
  DESCR("current xlog insert location");
! DATA(insert OID = 2850 ( pg_xlogfile_name_offset	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2249 "25" "{25,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
  DESCR("xlog filename and byte offset, given an xlog location");
! DATA(insert OID = 2851 ( pg_xlogfile_name			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
  DESCR("xlog filename, given an xlog location");
  
! DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "25 25" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
  DESCR("difference in bytes, given two xlog locations");
  
  DATA(insert OID = 3809 ( pg_export_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
--- 2971,2998 ----
  DESCR("cancel a server process' current query");
  DATA(insert OID = 2096 ( pg_terminate_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 16 "23" _null_ _null_ _null_ _null_ pg_terminate_backend _null_ _null_ _null_ ));
  DESCR("terminate a server process");
! DATA(insert OID = 2172 ( pg_start_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 3220 "25 16" _null_ _null_ _null_ _null_ pg_start_backup _null_ _null_ _null_ ));
  DESCR("prepare for taking an online backup");
! DATA(insert OID = 2173 ( pg_stop_backup			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_stop_backup _null_ _null_ _null_ ));
  DESCR("finish taking an online backup");
  DATA(insert OID = 3813 ( pg_is_in_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_backup _null_ _null_ _null_ ));
  DESCR("true if server is in online backup");
  DATA(insert OID = 3814 ( pg_backup_start_time		PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_ pg_backup_start_time _null_ _null_ _null_ ));
  DESCR("start time of an online backup");
! DATA(insert OID = 2848 ( pg_switch_xlog			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_switch_xlog _null_ _null_ _null_ ));
  DESCR("switch to new xlog file");
! DATA(insert OID = 3098 ( pg_create_restore_point	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 3220 "25" _null_ _null_ _null_ _null_ pg_create_restore_point _null_ _null_ _null_ ));
  DESCR("create a named restore point");
! DATA(insert OID = 2849 ( pg_current_xlog_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_current_xlog_location _null_ _null_ _null_ ));
  DESCR("current xlog write location");
! DATA(insert OID = 2852 ( pg_current_xlog_insert_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
  DESCR("current xlog insert location");
! DATA(insert OID = 2850 ( pg_xlogfile_name_offset	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2249 "3220" "{3220,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
  DESCR("xlog filename and byte offset, given an xlog location");
! DATA(insert OID = 2851 ( pg_xlogfile_name			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "3220" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
  DESCR("xlog filename, given an xlog location");
  
! DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
  DESCR("difference in bytes, given two xlog locations");
  
  DATA(insert OID = 3809 ( pg_export_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
***************
*** 3001,3009 **** DESCR("export a snapshot");
  DATA(insert OID = 3810 (  pg_is_in_recovery		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_recovery _null_ _null_ _null_ ));
  DESCR("true if server is in recovery");
  
! DATA(insert OID = 3820 ( pg_last_xlog_receive_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_last_xlog_receive_location _null_ _null_ _null_ ));
  DESCR("current xlog flush location");
! DATA(insert OID = 3821 ( pg_last_xlog_replay_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_last_xlog_replay_location _null_ _null_ _null_ ));
  DESCR("last xlog replay location");
  DATA(insert OID = 3830 ( pg_last_xact_replay_timestamp	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 1184 "" _null_ _null_ _null_ _null_ pg_last_xact_replay_timestamp _null_ _null_ _null_ ));
  DESCR("timestamp of last replay xact");
--- 3001,3009 ----
  DATA(insert OID = 3810 (  pg_is_in_recovery		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_recovery _null_ _null_ _null_ ));
  DESCR("true if server is in recovery");
  
! DATA(insert OID = 3820 ( pg_last_xlog_receive_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_last_xlog_receive_location _null_ _null_ _null_ ));
  DESCR("current xlog flush location");
! DATA(insert OID = 3821 ( pg_last_xlog_replay_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_last_xlog_replay_location _null_ _null_ _null_ ));
  DESCR("last xlog replay location");
  DATA(insert OID = 3830 ( pg_last_xact_replay_timestamp	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 1184 "" _null_ _null_ _null_ _null_ pg_last_xact_replay_timestamp _null_ _null_ _null_ ));
  DESCR("timestamp of last replay xact");
***************
*** 4800,4810 **** DATA(insert OID = 3473 (  spg_range_quad_leaf_consistent	PGNSP PGUID 12 1 0 0 0
  DESCR("SP-GiST support for quad tree over range");
  
  /* replication slots */
! DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2249 "19" "{19,25,25}" "{i,o,o}" "{slotname,slotname,xlog_position}" _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
  DESCR("create a physical replication slot");
  DATA(insert OID = 3780 (  pg_drop_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "19" _null_ _null_ _null_ _null_ pg_drop_replication_slot _null_ _null_ _null_ ));
  DESCR("drop a replication slot");
! DATA(insert OID = 3781 (  pg_get_replication_slots	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{25,25,26,16,28,25}" "{o,o,o,o,o,o}" "{slot_name,slot_type,datoid,active,xmin,restart_lsn}" _null_ pg_get_replication_slots _null_ _null_ _null_ ));
  DESCR("information about replication slots currently in use");
  
  /* event triggers */
--- 4800,4810 ----
  DESCR("SP-GiST support for quad tree over range");
  
  /* replication slots */
! DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2249 "19" "{19,25,3220}" "{i,o,o}" "{slotname,slotname,xlog_position}" _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
  DESCR("create a physical replication slot");
  DATA(insert OID = 3780 (  pg_drop_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "19" _null_ _null_ _null_ _null_ pg_drop_replication_slot _null_ _null_ _null_ ));
  DESCR("drop a replication slot");
! DATA(insert OID = 3781 (  pg_get_replication_slots	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{25,25,26,16,28,3220}" "{o,o,o,o,o,o}" "{slot_name,slot_type,datoid,active,xmin,restart_lsn}" _null_ pg_get_replication_slots _null_ _null_ _null_ ));
  DESCR("information about replication slots currently in use");
  
  /* event triggers */

*** a/doc/src/sgml/datatype.sgml
--- b/doc/src/sgml/datatype.sgml
***************
*** 181,186 ****
--- 181,192 ----
        </row>
  
        <row>
+        <entry><type>pglsn</type></entry>
+        <entry></entry>
+        <entry><productname>PostgreSQL</productname> Log Sequence Number</entry>
+       </row>
+ 
+       <row>
         <entry><type>point</type></entry>
         <entry></entry>
         <entry>geometric point on a plane</entry>
***************
*** 4502,4507 **** SELECT * FROM pg_attribute
--- 4508,4528 ----
     </para>
    </sect1>
  
+   <sect1 id="datatype-pglsn">
+    <title><acronym>PGLSN Type</title>
+ 
+    <indexterm zone="datatype-pglsn">
+     <primary>PGLSN</primary>
+    </indexterm>
+ 
+    <para>
+     The <type>pglsn</type> data type can be used to store LSN (Log Sequence
+     Number) data which is a pointer to a location in the XLOG. This type is a
+     representation of XLogRecPtr and an internal system type of
+     <productname>PostgreSQL</productname>.
+    </para>
+   </sect1>
+ 
    <sect1 id="datatype-pseudo">
     <title>Pseudo-Types</title>
  
*** a/src/backend/utils/adt/Makefile
--- b/src/backend/utils/adt/Makefile
***************
*** 21,27 **** OBJS = acl.o arrayfuncs.o array_selfuncs.o array_typanalyze.o \
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
  	lockfuncs.o misc.o nabstime.o name.o numeric.o numutils.o \
! 	oid.o oracle_compat.o orderedsetaggs.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
  	tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
--- 21,27 ----
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
  	lockfuncs.o misc.o nabstime.o name.o numeric.o numutils.o \
! 	oid.o oracle_compat.o orderedsetaggs.o pglsn.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
  	tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
*** /dev/null
--- b/src/backend/utils/adt/pglsn.c
***************
*** 0 ****
--- 1,180 ----
+ /*-------------------------------------------------------------------------
+  *
+  * pglsn.c
+  *	  Internal PostgreSQL LSN operations
+  *
+  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * IDENTIFICATION
+  *	  src/backend/utils/adt/pglsn.c
+  *
+  *-------------------------------------------------------------------------
+  */
+ #include "postgres.h"
+ 
+ #include "funcapi.h"
+ #include "libpq/pqformat.h"
+ #include "utils/builtins.h"
+ #include "utils/pglsn.h"
+ 
+ #define MAXPGLSNLEN			17
+ #define MAXPGLSNCOMPONENT	8
+ 
+ /*----------------------------------------------------------
+  * Formatting and conversion routines.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ pglsn_in(PG_FUNCTION_ARGS)
+ {
+ 	char	   *str = PG_GETARG_CSTRING(0);
+ 	int			len1, len2;
+ 	uint32		id, off;
+ 	XLogRecPtr	result;
+ 
+ 	/* Sanity check input format. */
+ 	len1 = strspn(str, "0123456789abcdefABCDEF");
+ 	if (len1 < 1 || len1 > MAXPGLSNCOMPONENT || str[len1] != '/')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ 	len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
+ 	if (len2 < 1 || len2 > MAXPGLSNCOMPONENT || str[len1 + 1 + len2] != '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ 
+ 	/* Decode result. */
+ 	id = (uint32) strtoul(str, NULL, 16);
+ 	off = (uint32) strtoul(str + len1 + 1, NULL, 16);
+ 	result = (XLogRecPtr) ((uint64) id << 32) | off;
+ 
+ 	PG_RETURN_PGLSN(result);
+ }
+ 
+ Datum
+ pglsn_out(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr	lsn = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	char		buf[MAXPGLSNLEN + 1];
+ 	char	   *result;
+ 	uint32		id, off;
+ 
+ 	/* Decode ID and offset */
+ 	id = (uint32) (lsn >> 32);
+ 	off = (uint32) lsn;
+ 
+ 	sprintf(buf, "%X/%X", id, off);
+ 	result = pstrdup(buf);
+ 	PG_RETURN_CSTRING(result);
+ }
+ 
+ Datum
+ pglsn_recv(PG_FUNCTION_ARGS)
+ {
+ 	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+ 	XLogRecPtr	result;
+ 
+ 	result = pq_getmsgint64(buf);
+ 	PG_RETURN_PGLSN(result);
+ }
+ 
+ Datum
+ pglsn_send(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	StringInfoData buf;
+ 
+ 	pq_begintypsend(&buf);
+ 	pq_sendint64(&buf, lsn);
+ 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Operators for PostgreSQL LSNs
+  *---------------------------------------------------------*/
+ 
+ Datum
+ pglsn_eq(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 == lsn2);
+ }
+ 
+ Datum
+ pglsn_ne(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 != lsn2);
+ }
+ 
+ Datum
+ pglsn_lt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 < lsn2);
+ }
+ 
+ Datum
+ pglsn_gt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 > lsn2);
+ }
+ 
+ Datum
+ pglsn_le(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 <= lsn2);
+ }
+ 
+ Datum
+ pglsn_ge(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 >= lsn2);
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Arithmetic operators on PostgreSQL LSNs.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ pglsn_mi(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PGLSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PGLSN(1);
+ 	char		buf[256];
+ 	Datum		result;
+ 
+ 	/* Negative results are not allowed. */
+ 	if (lsn1 < lsn2)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ 				 errmsg("transaction log location out of range")));
+ 
+ 	/* Convert to numeric. */
+ 	sprintf(buf, UINT64_FORMAT, lsn1 - lsn2);
+ 	result = DirectFunctionCall3(numeric_in,
+ 								 CStringGetDatum(buf),
+ 								 ObjectIdGetDatum(0),
+ 								 Int32GetDatum(-1));
+ 
+ 	return result;
+ }
*** a/src/include/catalog/pg_operator.h
--- b/src/include/catalog/pg_operator.h
***************
*** 1592,1597 **** DESCR("less than or equal");
--- 1592,1613 ----
  DATA(insert OID = 2977 (  ">="	   PGNSP PGUID b f f 2950 2950 16 2976 2974 uuid_ge scalargtsel scalargtjoinsel ));
  DESCR("greater than or equal");
  
+ /* pglsn operators */
+ DATA(insert OID = 3222 (  "="	   PGNSP PGUID b f f 3220 3220 16 3222 3223 pglsn_eq eqsel eqjoinsel ));
+ DESCR("equal");
+ DATA(insert OID = 3223 (  "<>"	   PGNSP PGUID b f f 3220 3220 16 3223 3222 pglsn_ne neqsel neqjoinsel ));
+ DESCR("not equal");
+ DATA(insert OID = 3224 (  "<"	   PGNSP PGUID b f f 3220 3220 16 3225 3227 pglsn_lt scalarltsel scalarltjoinsel ));
+ DESCR("less than");
+ DATA(insert OID = 3225 (  ">"	   PGNSP PGUID b f f 3220 3220 16 3224 3226 pglsn_gt scalargtsel scalargtjoinsel ));
+ DESCR("greater than");
+ DATA(insert OID = 3226 (  "<="	   PGNSP PGUID b f f 3220 3220 16 3227 3225 pglsn_le scalarltsel scalarltjoinsel ));
+ DESCR("less than or equal");
+ DATA(insert OID = 3227 (  ">="	   PGNSP PGUID b f f 3220 3220 16 3226 3224 pglsn_ge scalargtsel scalargtjoinsel ));
+ DESCR("greater than or equal");
+ DATA(insert OID = 3228 (  "-"	   PGNSP PGUID b f f 3220 3220 1700    0	0 pglsn_mi - - ));
+ DESCR("minus");
+ 
  /* enum operators */
  DATA(insert OID = 3516 (  "="	   PGNSP PGUID b t t 3500 3500 16 3516 3517 enum_eq eqsel eqjoinsel ));
  DESCR("equal");
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 4212,4217 **** DESCR("I/O");
--- 4212,4234 ----
  DATA(insert OID = 2963 (  uuid_hash		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "2950" _null_ _null_ _null_ _null_ uuid_hash _null_ _null_ _null_ ));
  DESCR("hash");
  
+ /* pglsn */
+ DATA(insert OID = 3229 (  pglsn_in		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2275" _null_ _null_ _null_ _null_ pglsn_in _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3230 (  pglsn_out		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2275 "3220" _null_ _null_ _null_ _null_ pglsn_out _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3231 (  pglsn_lt		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pglsn_lt _null_ _null_ _null_ ));
+ DATA(insert OID = 3232 (  pglsn_le		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pglsn_le _null_ _null_ _null_ ));
+ DATA(insert OID = 3233 (  pglsn_eq		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pglsn_eq _null_ _null_ _null_ ));
+ DATA(insert OID = 3234 (  pglsn_ge		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pglsn_ge _null_ _null_ _null_ ));
+ DATA(insert OID = 3235 (  pglsn_gt		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pglsn_gt _null_ _null_ _null_ ));
+ DATA(insert OID = 3236 (  pglsn_ne		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pglsn_ne _null_ _null_ _null_ ));
+ DATA(insert OID = 3237 (  pglsn_mi		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ pglsn_mi _null_ _null_ _null_ ));
+ DATA(insert OID = 3238 (  pglsn_recv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2281" _null_ _null_ _null_ _null_ pglsn_recv _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3239 (  pglsn_send	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 17 "3220" _null_ _null_ _null_ _null_ pglsn_send _null_ _null_ _null_ ));
+ DESCR("I/O");
+ 
  /* enum related procs */
  DATA(insert OID = 3504 (  anyenum_in	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3500 "2275" _null_ _null_ _null_ _null_ anyenum_in _null_ _null_ _null_ ));
  DESCR("I/O");
*** a/src/include/catalog/pg_type.h
--- b/src/include/catalog/pg_type.h
***************
*** 577,582 **** DESCR("UUID datatype");
--- 577,587 ----
  #define UUIDOID 2950
  DATA(insert OID = 2951 ( _uuid			PGNSP PGUID -1 f b A f t \054 0 2950 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  
+ /* pglsn */
+ DATA(insert OID = 3220 ( pglsn			PGNSP PGUID 8 t b U t t \054 0 0 3221 pglsn_in pglsn_out pglsn_recv pglsn_send - - - d p f 0 -1 0 0 _null_ _null_ _null_ ));
+ DESCR("LSN datatype");
+ DATA(insert OID = 3221 ( _pglsn			PGNSP PGUID -1 f b A f t \054 0 3220 0 array_in array_out array_recv array_send - - array_typanalyze d x f 0 -1 0 0 _null_ _null_ _null_ ));
+ 
  /* text search */
  DATA(insert OID = 3614 ( tsvector		PGNSP PGUID -1 f b U f t \054 0 0 3643 tsvectorin tsvectorout tsvectorrecv tsvectorsend - - ts_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  DESCR("text representation for text search");
*** a/src/include/fmgr.h
--- b/src/include/fmgr.h
***************
*** 230,235 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 230,236 ----
  #define PG_GETARG_CHAR(n)	 DatumGetChar(PG_GETARG_DATUM(n))
  #define PG_GETARG_BOOL(n)	 DatumGetBool(PG_GETARG_DATUM(n))
  #define PG_GETARG_OID(n)	 DatumGetObjectId(PG_GETARG_DATUM(n))
+ #define PG_GETARG_PGLSN(n)	 DatumGetPGLSN(PG_GETARG_DATUM(n))
  #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
  #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
  #define PG_GETARG_NAME(n)	 DatumGetName(PG_GETARG_DATUM(n))
***************
*** 302,307 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 303,309 ----
  #define PG_RETURN_CHAR(x)	 return CharGetDatum(x)
  #define PG_RETURN_BOOL(x)	 return BoolGetDatum(x)
  #define PG_RETURN_OID(x)	 return ObjectIdGetDatum(x)
+ #define PG_RETURN_PGLSN(x)	 return PGLSNGetDatum(x)
  #define PG_RETURN_POINTER(x) return PointerGetDatum(x)
  #define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
  #define PG_RETURN_NAME(x)	 return NameGetDatum(x)
*** a/src/include/postgres.h
--- b/src/include/postgres.h
***************
*** 484,489 **** typedef Datum *DatumPtr;
--- 484,503 ----
  #define ObjectIdGetDatum(X) ((Datum) SET_4_BYTES(X))
  
  /*
+  * DatumGetPGLSN
+  *		Returns PostgreSQL log sequence number of a datum.
+  */
+ 
+ #define DatumGetPGLSN(X) ((XLogRecPtr) GET_8_BYTES(X))
+ 
+ /*
+  * PGLSNGetDatum
+  *		Returns datum representation for a PostgreSQL log sequence number.
+  */
+ 
+ #define PGLSNGetDatum(X) ((Datum) SET_8_BYTES(X))
+ 
+ /*
   * DatumGetTransactionId
   *		Returns transaction identifier value of a datum.
   */
*** /dev/null
--- b/src/include/utils/pglsn.h
***************
*** 0 ****
--- 1,34 ----
+ /*-------------------------------------------------------------------------
+  *
+  * pglsn.h
+  *		Declarations for operations on log sequence numbers (LSNs) of
+  *		PostgreSQL.
+  *
+  *
+  * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * src/include/utils/pglsn.h
+  *
+  *-------------------------------------------------------------------------
+  */
+ #ifndef PGLSN_H
+ #define PGLSN_H
+ 
+ #include "fmgr.h"
+ 
+ extern Datum pglsn_in(PG_FUNCTION_ARGS);
+ extern Datum pglsn_out(PG_FUNCTION_ARGS);
+ extern Datum pglsn_recv(PG_FUNCTION_ARGS);
+ extern Datum pglsn_send(PG_FUNCTION_ARGS);
+ 
+ extern Datum pglsn_eq(PG_FUNCTION_ARGS);
+ extern Datum pglsn_ne(PG_FUNCTION_ARGS);
+ extern Datum pglsn_lt(PG_FUNCTION_ARGS);
+ extern Datum pglsn_gt(PG_FUNCTION_ARGS);
+ extern Datum pglsn_le(PG_FUNCTION_ARGS);
+ extern Datum pglsn_ge(PG_FUNCTION_ARGS);
+ 
+ extern Datum pglsn_mi(PG_FUNCTION_ARGS);
+ 
+ #endif   /* PGLSN_H */
*** /dev/null
--- b/src/test/regress/expected/pglsn.out
***************
*** 0 ****
--- 1,62 ----
+ --
+ -- PGLSN
+ --
+ CREATE TABLE PGLSN_TBL (f1 pglsn);
+ -- Largest and smallest input
+ INSERT INTO PGLSN_TBL VALUES ('0/0');
+ INSERT INTO PGLSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ -- Incorrect input
+ INSERT INTO PGLSN_TBL VALUES ('G/0');
+ ERROR:  invalid input syntax for transaction log location: "G/0"
+ LINE 1: INSERT INTO PGLSN_TBL VALUES ('G/0');
+                                       ^
+ INSERT INTO PGLSN_TBL VALUES ('-1/0');
+ ERROR:  invalid input syntax for transaction log location: "-1/0"
+ LINE 1: INSERT INTO PGLSN_TBL VALUES ('-1/0');
+                                       ^
+ INSERT INTO PGLSN_TBL VALUES (' 0/12345678');
+ ERROR:  invalid input syntax for transaction log location: " 0/12345678"
+ LINE 1: INSERT INTO PGLSN_TBL VALUES (' 0/12345678');
+                                       ^
+ INSERT INTO PGLSN_TBL VALUES ('ABCD/');
+ ERROR:  invalid input syntax for transaction log location: "ABCD/"
+ LINE 1: INSERT INTO PGLSN_TBL VALUES ('ABCD/');
+                                       ^
+ INSERT INTO PGLSN_TBL VALUES ('/ABCD');
+ ERROR:  invalid input syntax for transaction log location: "/ABCD"
+ LINE 1: INSERT INTO PGLSN_TBL VALUES ('/ABCD');
+                                       ^
+ DROP TABLE PGLSN_TBL;
+ -- Operators
+ SELECT pglsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+  pglsn_eq 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pglsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+  pglsn_ne 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pglsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+  pglsn_lt 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pglsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+  pglsn_gt 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pglsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ ERROR:  transaction log location out of range
+ SELECT pglsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct
+  pglsn_mi 
+ ----------
+         1
+ (1 row)
+ 
*** a/src/test/regress/parallel_schedule
--- b/src/test/regress/parallel_schedule
***************
*** 13,19 **** test: tablespace
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes
  
  # Depends on things setup during char, varchar and text
  test: strings
--- 13,19 ----
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes pglsn
  
  # Depends on things setup during char, varchar and text
  test: strings
*** a/src/test/regress/serial_schedule
--- b/src/test/regress/serial_schedule
***************
*** 19,24 **** test: uuid
--- 19,25 ----
  test: enum
  test: money
  test: rangetypes
+ test: pglsn
  test: strings
  test: numerology
  test: point
*** /dev/null
--- b/src/test/regress/sql/pglsn.sql
***************
*** 0 ****
--- 1,25 ----
+ --
+ -- PGLSN
+ --
+ 
+ CREATE TABLE PGLSN_TBL (f1 pglsn);
+ 
+ -- Largest and smallest input
+ INSERT INTO PGLSN_TBL VALUES ('0/0');
+ INSERT INTO PGLSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ 
+ -- Incorrect input
+ INSERT INTO PGLSN_TBL VALUES ('G/0');
+ INSERT INTO PGLSN_TBL VALUES ('-1/0');
+ INSERT INTO PGLSN_TBL VALUES (' 0/12345678');
+ INSERT INTO PGLSN_TBL VALUES ('ABCD/');
+ INSERT INTO PGLSN_TBL VALUES ('/ABCD');
+ DROP TABLE PGLSN_TBL;
+ 
+ -- Operators
+ SELECT pglsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+ SELECT pglsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT pglsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+ SELECT pglsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT pglsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ SELECT pglsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index dca24fc..49c20e2 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -5244,7 +5244,7 @@
 
      <row>
       <entry><structfield>restart_lsn</structfield></entry>
-      <entry><type>text</type></entry>
+      <entry><type>pglsn</type></entry>
       <entry></entry>
       <entry>The address (<literal>LSN</literal>) of oldest WAL which still
       might be required by the consumer of this slot and thus won't be
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be548d7..c7ac74b 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -15884,35 +15884,35 @@ SELECT set_config('log_statement_stats', 'off', false);
        <entry>
         <literal><function>pg_create_restore_point(<parameter>name</> <type>text</>)</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Create a named point for performing restore (restricted to superusers)</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_current_xlog_insert_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Get current transaction log insert location</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_current_xlog_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Get current transaction log write location</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_start_backup(<parameter>label</> <type>text</> <optional>, <parameter>fast</> <type>boolean</> </optional>)</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Prepare for performing on-line backup (restricted to superusers or replication roles)</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_stop_backup()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Finish performing on-line backup (restricted to superusers or replication roles)</entry>
       </row>
       <row>
@@ -15933,26 +15933,26 @@ SELECT set_config('log_statement_stats', 'off', false);
        <entry>
         <literal><function>pg_switch_xlog()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Force switch to a new transaction log file (restricted to superusers)</entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_xlogfile_name(<parameter>location</> <type>text</>)</function></literal>
+        <literal><function>pg_xlogfile_name(<parameter>location</> <type>pglsn</>)</function></literal>
         </entry>
        <entry><type>text</type></entry>
        <entry>Convert transaction log location string to file name</entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_xlogfile_name_offset(<parameter>location</> <type>text</>)</function></literal>
+        <literal><function>pg_xlogfile_name_offset(<parameter>location</> <type>pglsn</>)</function></literal>
         </entry>
        <entry><type>text</>, <type>integer</></entry>
        <entry>Convert transaction log location string to file name and decimal byte offset within file</entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_xlog_location_diff(<parameter>location</> <type>text</>, <parameter>location</> <type>text</>)</function></literal>
+        <literal><function>pg_xlog_location_diff(<parameter>location</> <type>pglsn</>, <parameter>location</> <type>pglsn</>)</function></literal>
        </entry>
        <entry><type>numeric</></entry>
        <entry>Calculate the difference between two transaction log locations</entry>
@@ -16107,7 +16107,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
        <entry>
         <literal><function>pg_last_xlog_receive_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Get last transaction log location received and synced to disk by
         streaming replication. While streaming replication is in progress
         this will increase monotonically. If recovery has completed this will
@@ -16121,7 +16121,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
        <entry>
         <literal><function>pg_last_xlog_replay_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pglsn</type></entry>
        <entry>Get last transaction log location replayed during recovery.
         If recovery is still in progress this will increase monotonically.
         If recovery has completed then this value will remain static at
@@ -16335,7 +16335,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         <literal><function>pg_create_physical_replication_slot(<parameter>slotname</parameter> <type>text</type>, <parameter>plugin</parameter> <type>text</type>)</function></literal>
        </entry>
        <entry>
-        (<parameter>slotname</parameter> <type>text</type>, <parameter>xlog_position</parameter> <type>text</type>)
+        (<parameter>slotname</parameter> <type>text</type>, <parameter>xlog_position</parameter> <type>pglsn</type>)
        </entry>
        <entry>
         Creates a new physical replication slot named
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index 9133179..830586c 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -33,8 +33,6 @@
 #include "utils/timestamp.h"
 #include "storage/fd.h"
 
-static void validate_xlog_location(char *str);
-
 
 /*
  * pg_start_backup: set up for taking an on-line backup dump
@@ -52,7 +50,6 @@ pg_start_backup(PG_FUNCTION_ARGS)
 	bool		fast = PG_GETARG_BOOL(1);
 	char	   *backupidstr;
 	XLogRecPtr	startpoint;
-	char		startxlogstr[MAXFNAMELEN];
 
 	backupidstr = text_to_cstring(backupid);
 
@@ -63,9 +60,7 @@ pg_start_backup(PG_FUNCTION_ARGS)
 
 	startpoint = do_pg_start_backup(backupidstr, fast, NULL, NULL);
 
-	snprintf(startxlogstr, sizeof(startxlogstr), "%X/%X",
-			 (uint32) (startpoint >> 32), (uint32) startpoint);
-	PG_RETURN_TEXT_P(cstring_to_text(startxlogstr));
+	PG_RETURN_PGLSN(startpoint);
 }
 
 /*
@@ -85,7 +80,6 @@ Datum
 pg_stop_backup(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	stoppoint;
-	char		stopxlogstr[MAXFNAMELEN];
 
 	if (!superuser() && !has_rolreplication(GetUserId()))
 		ereport(ERROR,
@@ -94,9 +88,7 @@ pg_stop_backup(PG_FUNCTION_ARGS)
 
 	stoppoint = do_pg_stop_backup(NULL, true, NULL);
 
-	snprintf(stopxlogstr, sizeof(stopxlogstr), "%X/%X",
-			 (uint32) (stoppoint >> 32), (uint32) stoppoint);
-	PG_RETURN_TEXT_P(cstring_to_text(stopxlogstr));
+	PG_RETURN_PGLSN(stoppoint);
 }
 
 /*
@@ -124,9 +116,7 @@ pg_switch_xlog(PG_FUNCTION_ARGS)
 	/*
 	 * As a convenience, return the WAL location of the switch record
 	 */
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (switchpoint >> 32), (uint32) switchpoint);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PGLSN(switchpoint);
 }
 
 /*
@@ -169,9 +159,7 @@ pg_create_restore_point(PG_FUNCTION_ARGS)
 	/*
 	 * As a convenience, return the WAL location of the restore point record
 	 */
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (restorepoint >> 32), (uint32) restorepoint);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PGLSN(restorepoint);
 }
 
 /*
@@ -185,7 +173,6 @@ Datum
 pg_current_xlog_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	current_recptr;
-	char		location[MAXFNAMELEN];
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -195,9 +182,7 @@ pg_current_xlog_location(PG_FUNCTION_ARGS)
 
 	current_recptr = GetXLogWriteRecPtr();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (current_recptr >> 32), (uint32) current_recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PGLSN(current_recptr);
 }
 
 /*
@@ -209,7 +194,6 @@ Datum
 pg_current_xlog_insert_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	current_recptr;
-	char		location[MAXFNAMELEN];
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -219,9 +203,7 @@ pg_current_xlog_insert_location(PG_FUNCTION_ARGS)
 
 	current_recptr = GetXLogInsertRecPtr();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (current_recptr >> 32), (uint32) current_recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PGLSN(current_recptr);
 }
 
 /*
@@ -234,16 +216,13 @@ Datum
 pg_last_xlog_receive_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	recptr;
-	char		location[MAXFNAMELEN];
 
 	recptr = GetWalRcvWriteRecPtr(NULL, NULL);
 
 	if (recptr == 0)
 		PG_RETURN_NULL();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (recptr >> 32), (uint32) recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PGLSN(recptr);
 }
 
 /*
@@ -256,16 +235,13 @@ Datum
 pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	recptr;
-	char		location[MAXFNAMELEN];
 
 	recptr = GetXLogReplayRecPtr(NULL);
 
 	if (recptr == 0)
 		PG_RETURN_NULL();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (recptr >> 32), (uint32) recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PGLSN(recptr);
 }
 
 /*
@@ -279,13 +255,11 @@ pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
 Datum
 pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
 {
-	text	   *location = PG_GETARG_TEXT_P(0);
-	char	   *locationstr;
 	uint32		hi,
 				lo;
 	XLogSegNo	xlogsegno;
 	uint32		xrecoff;
-	XLogRecPtr	locationpoint;
+	XLogRecPtr	locationpoint = PG_GETARG_PGLSN(0);
 	char		xlogfilename[MAXFNAMELEN];
 	Datum		values[2];
 	bool		isnull[2];
@@ -300,20 +274,6 @@ pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
 				 errhint("pg_xlogfile_name_offset() cannot be executed during recovery.")));
 
 	/*
-	 * Read input and parse
-	 */
-	locationstr = text_to_cstring(location);
-
-	validate_xlog_location(locationstr);
-
-	if (sscanf(locationstr, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("could not parse transaction log location \"%s\"",
-						locationstr)));
-	locationpoint = ((uint64) hi) << 32 | lo;
-
-	/*
 	 * Construct a tuple descriptor for the result row.  This must match this
 	 * function's pg_proc entry!
 	 */
@@ -359,12 +319,10 @@ pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
 Datum
 pg_xlogfile_name(PG_FUNCTION_ARGS)
 {
-	text	   *location = PG_GETARG_TEXT_P(0);
-	char	   *locationstr;
 	uint32		hi,
 				lo;
 	XLogSegNo	xlogsegno;
-	XLogRecPtr	locationpoint;
+	XLogRecPtr	locationpoint = PG_GETARG_PGLSN(0);
 	char		xlogfilename[MAXFNAMELEN];
 
 	if (RecoveryInProgress())
@@ -373,17 +331,6 @@ pg_xlogfile_name(PG_FUNCTION_ARGS)
 				 errmsg("recovery is in progress"),
 		 errhint("pg_xlogfile_name() cannot be executed during recovery.")));
 
-	locationstr = text_to_cstring(location);
-
-	validate_xlog_location(locationstr);
-
-	if (sscanf(locationstr, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("could not parse transaction log location \"%s\"",
-						locationstr)));
-	locationpoint = ((uint64) hi) << 32 | lo;
-
 	XLByteToPrevSeg(locationpoint, xlogsegno);
 	XLogFileName(xlogfilename, ThisTimeLineID, xlogsegno);
 
@@ -482,77 +429,27 @@ pg_is_in_recovery(PG_FUNCTION_ARGS)
 }
 
 /*
- * Validate the text form of a transaction log location.
- * (Just using sscanf() input allows incorrect values such as
- * negatives, so we have to be a bit more careful about that).
- */
-static void
-validate_xlog_location(char *str)
-{
-#define MAXLSNCOMPONENT		8
-
-	int			len1,
-				len2;
-
-	len1 = strspn(str, "0123456789abcdefABCDEF");
-	if (len1 < 1 || len1 > MAXLSNCOMPONENT || str[len1] != '/')
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
-
-	len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
-	if (len2 < 1 || len2 > MAXLSNCOMPONENT || str[len1 + 1 + len2] != '\0')
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
-}
-
-/*
  * Compute the difference in bytes between two WAL locations.
  */
 Datum
 pg_xlog_location_diff(PG_FUNCTION_ARGS)
 {
-	text	   *location1 = PG_GETARG_TEXT_P(0);
-	text	   *location2 = PG_GETARG_TEXT_P(1);
-	char	   *str1,
-			   *str2;
-	XLogRecPtr	loc1,
-				loc2;
+	XLogRecPtr	loc1 = PG_GETARG_PGLSN(0);
+	XLogRecPtr	loc2 = PG_GETARG_PGLSN(1);
 	Numeric		result;
 	uint64		bytes1,
 				bytes2;
 	uint32		hi,
 				lo;
 
-	/*
-	 * Read and parse input
-	 */
-	str1 = text_to_cstring(location1);
-	str2 = text_to_cstring(location2);
-
-	validate_xlog_location(str1);
-	validate_xlog_location(str2);
-
-	if (sscanf(str1, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-		   errmsg("could not parse transaction log location \"%s\"", str1)));
-	loc1 = ((uint64) hi) << 32 | lo;
-
-	if (sscanf(str2, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-		   errmsg("could not parse transaction log location \"%s\"", str2)));
-	loc2 = ((uint64) hi) << 32 | lo;
-
 	bytes1 = (uint64) loc1;
 	bytes2 = (uint64) loc2;
 
 	/*
 	 * result = bytes1 - bytes2.
 	 *
-	 * XXX: this won't handle values higher than 2^63 correctly.
+	 * XXX: this won't handle values higher than 2^63 correctly and can
+	 * return negative values.
 	 */
 	result = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
 			DirectFunctionCall1(int8_numeric, Int64GetDatum((int64) bytes1)),
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index f02efec..04f8afb 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -810,7 +810,7 @@ COMMENT ON FUNCTION ts_debug(text) IS
 
 CREATE OR REPLACE FUNCTION
   pg_start_backup(label text, fast boolean DEFAULT false)
-  RETURNS text STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
+  RETURNS pglsn STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
 
 CREATE OR REPLACE FUNCTION
   json_populate_record(base anyelement, from_json json, use_json_as_text boolean DEFAULT false)
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index 98a860e..f960113 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -141,8 +141,6 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
 		bool		active;
 		Oid			database;
 		const char *slot_name;
-
-		char		restart_lsn_s[MAXFNAMELEN];
 		int			i;
 
 		SpinLockAcquire(&slot->mutex);
@@ -164,9 +162,6 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
 
 		memset(nulls, 0, sizeof(nulls));
 
-		snprintf(restart_lsn_s, sizeof(restart_lsn_s), "%X/%X",
-				 (uint32) (restart_lsn >> 32), (uint32) restart_lsn);
-
 		i = 0;
 		values[i++] = CStringGetTextDatum(slot_name);
 		if (database == InvalidOid)
@@ -180,7 +175,7 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
 		else
 			nulls[i++] = true;
 		if (restart_lsn != InvalidTransactionId)
-			values[i++] = CStringGetTextDatum(restart_lsn_s);
+			values[i++] = PGLSNGetDatum(restart_lsn);
 		else
 			nulls[i++] = true;
 
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ece2692..feec455 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2971,28 +2971,28 @@ DATA(insert OID = 2171 ( pg_cancel_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v
 DESCR("cancel a server process' current query");
 DATA(insert OID = 2096 ( pg_terminate_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 16 "23" _null_ _null_ _null_ _null_ pg_terminate_backend _null_ _null_ _null_ ));
 DESCR("terminate a server process");
-DATA(insert OID = 2172 ( pg_start_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 25 "25 16" _null_ _null_ _null_ _null_ pg_start_backup _null_ _null_ _null_ ));
+DATA(insert OID = 2172 ( pg_start_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 3220 "25 16" _null_ _null_ _null_ _null_ pg_start_backup _null_ _null_ _null_ ));
 DESCR("prepare for taking an online backup");
-DATA(insert OID = 2173 ( pg_stop_backup			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_stop_backup _null_ _null_ _null_ ));
+DATA(insert OID = 2173 ( pg_stop_backup			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_stop_backup _null_ _null_ _null_ ));
 DESCR("finish taking an online backup");
 DATA(insert OID = 3813 ( pg_is_in_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_backup _null_ _null_ _null_ ));
 DESCR("true if server is in online backup");
 DATA(insert OID = 3814 ( pg_backup_start_time		PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_ pg_backup_start_time _null_ _null_ _null_ ));
 DESCR("start time of an online backup");
-DATA(insert OID = 2848 ( pg_switch_xlog			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_switch_xlog _null_ _null_ _null_ ));
+DATA(insert OID = 2848 ( pg_switch_xlog			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_switch_xlog _null_ _null_ _null_ ));
 DESCR("switch to new xlog file");
-DATA(insert OID = 3098 ( pg_create_restore_point	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 25 "25" _null_ _null_ _null_ _null_ pg_create_restore_point _null_ _null_ _null_ ));
+DATA(insert OID = 3098 ( pg_create_restore_point	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 3220 "25" _null_ _null_ _null_ _null_ pg_create_restore_point _null_ _null_ _null_ ));
 DESCR("create a named restore point");
-DATA(insert OID = 2849 ( pg_current_xlog_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_current_xlog_location _null_ _null_ _null_ ));
+DATA(insert OID = 2849 ( pg_current_xlog_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_current_xlog_location _null_ _null_ _null_ ));
 DESCR("current xlog write location");
-DATA(insert OID = 2852 ( pg_current_xlog_insert_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
+DATA(insert OID = 2852 ( pg_current_xlog_insert_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
 DESCR("current xlog insert location");
-DATA(insert OID = 2850 ( pg_xlogfile_name_offset	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2249 "25" "{25,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
+DATA(insert OID = 2850 ( pg_xlogfile_name_offset	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2249 "3220" "{3220,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
 DESCR("xlog filename and byte offset, given an xlog location");
-DATA(insert OID = 2851 ( pg_xlogfile_name			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
+DATA(insert OID = 2851 ( pg_xlogfile_name			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "3220" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
 DESCR("xlog filename, given an xlog location");
 
-DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "25 25" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
+DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
 DESCR("difference in bytes, given two xlog locations");
 
 DATA(insert OID = 3809 ( pg_export_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
@@ -3001,9 +3001,9 @@ DESCR("export a snapshot");
 DATA(insert OID = 3810 (  pg_is_in_recovery		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_recovery _null_ _null_ _null_ ));
 DESCR("true if server is in recovery");
 
-DATA(insert OID = 3820 ( pg_last_xlog_receive_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_last_xlog_receive_location _null_ _null_ _null_ ));
+DATA(insert OID = 3820 ( pg_last_xlog_receive_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_last_xlog_receive_location _null_ _null_ _null_ ));
 DESCR("current xlog flush location");
-DATA(insert OID = 3821 ( pg_last_xlog_replay_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_last_xlog_replay_location _null_ _null_ _null_ ));
+DATA(insert OID = 3821 ( pg_last_xlog_replay_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_last_xlog_replay_location _null_ _null_ _null_ ));
 DESCR("last xlog replay location");
 DATA(insert OID = 3830 ( pg_last_xact_replay_timestamp	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 1184 "" _null_ _null_ _null_ _null_ pg_last_xact_replay_timestamp _null_ _null_ _null_ ));
 DESCR("timestamp of last replay xact");
@@ -4800,11 +4800,11 @@ DATA(insert OID = 3473 (  spg_range_quad_leaf_consistent	PGNSP PGUID 12 1 0 0 0
 DESCR("SP-GiST support for quad tree over range");
 
 /* replication slots */
-DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2249 "19" "{19,25,25}" "{i,o,o}" "{slotname,slotname,xlog_position}" _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
+DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2249 "19" "{19,25,3220}" "{i,o,o}" "{slotname,slotname,xlog_position}" _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
 DESCR("create a physical replication slot");
 DATA(insert OID = 3780 (  pg_drop_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "19" _null_ _null_ _null_ _null_ pg_drop_replication_slot _null_ _null_ _null_ ));
 DESCR("drop a replication slot");
-DATA(insert OID = 3781 (  pg_get_replication_slots	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{25,25,26,16,28,25}" "{o,o,o,o,o,o}" "{slot_name,slot_type,datoid,active,xmin,restart_lsn}" _null_ pg_get_replication_slots _null_ _null_ _null_ ));
+DATA(insert OID = 3781 (  pg_get_replication_slots	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{25,25,26,16,28,3220}" "{o,o,o,o,o,o}" "{slot_name,slot_type,datoid,active,xmin,restart_lsn}" _null_ pg_get_replication_slots _null_ _null_ _null_ ));
 DESCR("information about replication slots currently in use");
 
 /* event triggers */

*** a/doc/src/sgml/datatype.sgml
--- b/doc/src/sgml/datatype.sgml
***************
*** 181,186 ****
--- 181,192 ----
        </row>
  
        <row>
+        <entry><type>pg_lsn</type></entry>
+        <entry></entry>
+        <entry><productname>PostgreSQL</productname> Log Sequence Number</entry>
+       </row>
+ 
+       <row>
         <entry><type>point</type></entry>
         <entry></entry>
         <entry>geometric point on a plane</entry>
***************
*** 4502,4507 **** SELECT * FROM pg_attribute
--- 4508,4528 ----
     </para>
    </sect1>
  
+   <sect1 id="datatype-pg-lsn">
+    <title><acronym>PG_LSN Type</title>
+ 
+    <indexterm zone="datatype-pg-lsn">
+     <primary>PG_LSN</primary>
+    </indexterm>
+ 
+    <para>
+     The <type>pg_lsn</type> data type can be used to store LSN (Log Sequence
+     Number) data which is a pointer to a location in the XLOG. This type is a
+     representation of XLogRecPtr and an internal system type of
+     <productname>PostgreSQL</productname>.
+    </para>
+   </sect1>
+ 
    <sect1 id="datatype-pseudo">
     <title>Pseudo-Types</title>
  
*** a/src/backend/utils/adt/Makefile
--- b/src/backend/utils/adt/Makefile
***************
*** 21,27 **** OBJS = acl.o arrayfuncs.o array_selfuncs.o array_typanalyze.o \
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
  	lockfuncs.o misc.o nabstime.o name.o numeric.o numutils.o \
! 	oid.o oracle_compat.o orderedsetaggs.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
  	tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
--- 21,27 ----
  	enum.o float.o format_type.o \
  	geo_ops.o geo_selfuncs.o int.o int8.o json.o jsonfuncs.o like.o \
  	lockfuncs.o misc.o nabstime.o name.o numeric.o numutils.o \
! 	oid.o oracle_compat.o orderedsetaggs.o pg_lsn.o \
  	pseudotypes.o rangetypes.o rangetypes_gist.o \
  	rowtypes.o regexp.o regproc.o ruleutils.o selfuncs.o \
  	tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
*** /dev/null
--- b/src/backend/utils/adt/pg_lsn.c
***************
*** 0 ****
--- 1,180 ----
+ /*-------------------------------------------------------------------------
+  *
+  * pg_lsn.c
+  *	  Internal PostgreSQL LSN operations
+  *
+  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * IDENTIFICATION
+  *	  src/backend/utils/adt/pg_lsn.c
+  *
+  *-------------------------------------------------------------------------
+  */
+ #include "postgres.h"
+ 
+ #include "funcapi.h"
+ #include "libpq/pqformat.h"
+ #include "utils/builtins.h"
+ #include "utils/pg_lsn.h"
+ 
+ #define MAXPG_LSNLEN			17
+ #define MAXPG_LSNCOMPONENT	8
+ 
+ /*----------------------------------------------------------
+  * Formatting and conversion routines.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ pg_lsn_in(PG_FUNCTION_ARGS)
+ {
+ 	char	   *str = PG_GETARG_CSTRING(0);
+ 	int			len1, len2;
+ 	uint32		id, off;
+ 	XLogRecPtr	result;
+ 
+ 	/* Sanity check input format. */
+ 	len1 = strspn(str, "0123456789abcdefABCDEF");
+ 	if (len1 < 1 || len1 > MAXPG_LSNCOMPONENT || str[len1] != '/')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ 	len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
+ 	if (len2 < 1 || len2 > MAXPG_LSNCOMPONENT || str[len1 + 1 + len2] != '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ 				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ 
+ 	/* Decode result. */
+ 	id = (uint32) strtoul(str, NULL, 16);
+ 	off = (uint32) strtoul(str + len1 + 1, NULL, 16);
+ 	result = (XLogRecPtr) ((uint64) id << 32) | off;
+ 
+ 	PG_RETURN_PG_LSN(result);
+ }
+ 
+ Datum
+ pg_lsn_out(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr	lsn = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	char		buf[MAXPG_LSNLEN + 1];
+ 	char	   *result;
+ 	uint32		id, off;
+ 
+ 	/* Decode ID and offset */
+ 	id = (uint32) (lsn >> 32);
+ 	off = (uint32) lsn;
+ 
+ 	sprintf(buf, "%X/%X", id, off);
+ 	result = pstrdup(buf);
+ 	PG_RETURN_CSTRING(result);
+ }
+ 
+ Datum
+ pg_lsn_recv(PG_FUNCTION_ARGS)
+ {
+ 	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+ 	XLogRecPtr	result;
+ 
+ 	result = pq_getmsgint64(buf);
+ 	PG_RETURN_PG_LSN(result);
+ }
+ 
+ Datum
+ pg_lsn_send(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	StringInfoData buf;
+ 
+ 	pq_begintypsend(&buf);
+ 	pq_sendint64(&buf, lsn);
+ 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Operators for PostgreSQL LSNs
+  *---------------------------------------------------------*/
+ 
+ Datum
+ pg_lsn_eq(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 == lsn2);
+ }
+ 
+ Datum
+ pg_lsn_ne(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 != lsn2);
+ }
+ 
+ Datum
+ pg_lsn_lt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 < lsn2);
+ }
+ 
+ Datum
+ pg_lsn_gt(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 > lsn2);
+ }
+ 
+ Datum
+ pg_lsn_le(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 <= lsn2);
+ }
+ 
+ Datum
+ pg_lsn_ge(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 
+ 	PG_RETURN_BOOL(lsn1 >= lsn2);
+ }
+ 
+ 
+ /*----------------------------------------------------------
+  *	Arithmetic operators on PostgreSQL LSNs.
+  *---------------------------------------------------------*/
+ 
+ Datum
+ pg_lsn_mi(PG_FUNCTION_ARGS)
+ {
+ 	XLogRecPtr lsn1 = (XLogRecPtr) PG_GETARG_PG_LSN(0);
+ 	XLogRecPtr lsn2 = (XLogRecPtr) PG_GETARG_PG_LSN(1);
+ 	char		buf[256];
+ 	Datum		result;
+ 
+ 	/* Negative results are not allowed. */
+ 	if (lsn1 < lsn2)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ 				 errmsg("transaction log location out of range")));
+ 
+ 	/* Convert to numeric. */
+ 	sprintf(buf, UINT64_FORMAT, lsn1 - lsn2);
+ 	result = DirectFunctionCall3(numeric_in,
+ 								 CStringGetDatum(buf),
+ 								 ObjectIdGetDatum(0),
+ 								 Int32GetDatum(-1));
+ 
+ 	return result;
+ }
*** a/src/include/catalog/pg_operator.h
--- b/src/include/catalog/pg_operator.h
***************
*** 1592,1597 **** DESCR("less than or equal");
--- 1592,1613 ----
  DATA(insert OID = 2977 (  ">="	   PGNSP PGUID b f f 2950 2950 16 2976 2974 uuid_ge scalargtsel scalargtjoinsel ));
  DESCR("greater than or equal");
  
+ /* pg_lsn operators */
+ DATA(insert OID = 3222 (  "="	   PGNSP PGUID b f f 3220 3220 16 3222 3223 pg_lsn_eq eqsel eqjoinsel ));
+ DESCR("equal");
+ DATA(insert OID = 3223 (  "<>"	   PGNSP PGUID b f f 3220 3220 16 3223 3222 pg_lsn_ne neqsel neqjoinsel ));
+ DESCR("not equal");
+ DATA(insert OID = 3224 (  "<"	   PGNSP PGUID b f f 3220 3220 16 3225 3227 pg_lsn_lt scalarltsel scalarltjoinsel ));
+ DESCR("less than");
+ DATA(insert OID = 3225 (  ">"	   PGNSP PGUID b f f 3220 3220 16 3224 3226 pg_lsn_gt scalargtsel scalargtjoinsel ));
+ DESCR("greater than");
+ DATA(insert OID = 3226 (  "<="	   PGNSP PGUID b f f 3220 3220 16 3227 3225 pg_lsn_le scalarltsel scalarltjoinsel ));
+ DESCR("less than or equal");
+ DATA(insert OID = 3227 (  ">="	   PGNSP PGUID b f f 3220 3220 16 3226 3224 pg_lsn_ge scalargtsel scalargtjoinsel ));
+ DESCR("greater than or equal");
+ DATA(insert OID = 3228 (  "-"	   PGNSP PGUID b f f 3220 3220 1700    0	0 pg_lsn_mi - - ));
+ DESCR("minus");
+ 
  /* enum operators */
  DATA(insert OID = 3516 (  "="	   PGNSP PGUID b t t 3500 3500 16 3516 3517 enum_eq eqsel eqjoinsel ));
  DESCR("equal");
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 4212,4217 **** DESCR("I/O");
--- 4212,4234 ----
  DATA(insert OID = 2963 (  uuid_hash		   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "2950" _null_ _null_ _null_ _null_ uuid_hash _null_ _null_ _null_ ));
  DESCR("hash");
  
+ /* pg_lsn */
+ DATA(insert OID = 3229 (  pg_lsn_in		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2275" _null_ _null_ _null_ _null_ pg_lsn_in _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3230 (  pg_lsn_out		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2275 "3220" _null_ _null_ _null_ _null_ pg_lsn_out _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3231 (  pg_lsn_lt		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_lt _null_ _null_ _null_ ));
+ DATA(insert OID = 3232 (  pg_lsn_le		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_le _null_ _null_ _null_ ));
+ DATA(insert OID = 3233 (  pg_lsn_eq		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_eq _null_ _null_ _null_ ));
+ DATA(insert OID = 3234 (  pg_lsn_ge		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_ge _null_ _null_ _null_ ));
+ DATA(insert OID = 3235 (  pg_lsn_gt		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_gt _null_ _null_ _null_ ));
+ DATA(insert OID = 3236 (  pg_lsn_ne		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 16 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_ne _null_ _null_ _null_ ));
+ DATA(insert OID = 3237 (  pg_lsn_mi		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_mi _null_ _null_ _null_ ));
+ DATA(insert OID = 3238 (  pg_lsn_recv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3220 "2281" _null_ _null_ _null_ _null_ pg_lsn_recv _null_ _null_ _null_ ));
+ DESCR("I/O");
+ DATA(insert OID = 3239 (  pg_lsn_send	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 17 "3220" _null_ _null_ _null_ _null_ pg_lsn_send _null_ _null_ _null_ ));
+ DESCR("I/O");
+ 
  /* enum related procs */
  DATA(insert OID = 3504 (  anyenum_in	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3500 "2275" _null_ _null_ _null_ _null_ anyenum_in _null_ _null_ _null_ ));
  DESCR("I/O");
*** a/src/include/catalog/pg_type.h
--- b/src/include/catalog/pg_type.h
***************
*** 577,582 **** DESCR("UUID datatype");
--- 577,587 ----
  #define UUIDOID 2950
  DATA(insert OID = 2951 ( _uuid			PGNSP PGUID -1 f b A f t \054 0 2950 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  
+ /* pg_lsn */
+ DATA(insert OID = 3220 ( pg_lsn			PGNSP PGUID 8 t b U t t \054 0 0 3221 pg_lsn_in pg_lsn_out pg_lsn_recv pg_lsn_send - - - d p f 0 -1 0 0 _null_ _null_ _null_ ));
+ DESCR("PostgreSQL LSN datatype");
+ DATA(insert OID = 3221 ( _pg_lsn			PGNSP PGUID -1 f b A f t \054 0 3220 0 array_in array_out array_recv array_send - - array_typanalyze d x f 0 -1 0 0 _null_ _null_ _null_ ));
+ 
  /* text search */
  DATA(insert OID = 3614 ( tsvector		PGNSP PGUID -1 f b U f t \054 0 0 3643 tsvectorin tsvectorout tsvectorrecv tsvectorsend - - ts_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
  DESCR("text representation for text search");
*** a/src/include/fmgr.h
--- b/src/include/fmgr.h
***************
*** 230,235 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 230,236 ----
  #define PG_GETARG_CHAR(n)	 DatumGetChar(PG_GETARG_DATUM(n))
  #define PG_GETARG_BOOL(n)	 DatumGetBool(PG_GETARG_DATUM(n))
  #define PG_GETARG_OID(n)	 DatumGetObjectId(PG_GETARG_DATUM(n))
+ #define PG_GETARG_PG_LSN(n)	 DatumGetPgLsn(PG_GETARG_DATUM(n))
  #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
  #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
  #define PG_GETARG_NAME(n)	 DatumGetName(PG_GETARG_DATUM(n))
***************
*** 302,307 **** extern struct varlena *pg_detoast_datum_packed(struct varlena * datum);
--- 303,309 ----
  #define PG_RETURN_CHAR(x)	 return CharGetDatum(x)
  #define PG_RETURN_BOOL(x)	 return BoolGetDatum(x)
  #define PG_RETURN_OID(x)	 return ObjectIdGetDatum(x)
+ #define PG_RETURN_PG_LSN(x)	 return PgLsnGetDatum(x)
  #define PG_RETURN_POINTER(x) return PointerGetDatum(x)
  #define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
  #define PG_RETURN_NAME(x)	 return NameGetDatum(x)
*** a/src/include/postgres.h
--- b/src/include/postgres.h
***************
*** 484,489 **** typedef Datum *DatumPtr;
--- 484,503 ----
  #define ObjectIdGetDatum(X) ((Datum) SET_4_BYTES(X))
  
  /*
+  * DatumGetPgLsn
+  *		Returns PostgreSQL log sequence number of a datum.
+  */
+ 
+ #define DatumGetPgLsn(X) ((XLogRecPtr) GET_8_BYTES(X))
+ 
+ /*
+  * PG_LSNGetDatum
+  *		Returns datum representation for a PostgreSQL log sequence number.
+  */
+ 
+ #define PgLsnGetDatum(X) ((Datum) SET_8_BYTES(X))
+ 
+ /*
   * DatumGetTransactionId
   *		Returns transaction identifier value of a datum.
   */
*** /dev/null
--- b/src/include/utils/pg_lsn.h
***************
*** 0 ****
--- 1,34 ----
+ /*-------------------------------------------------------------------------
+  *
+  * pg_lsn.h
+  *		Declarations for operations on log sequence numbers (LSNs) of
+  *		PostgreSQL.
+  *
+  *
+  * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+  * Portions Copyright (c) 1994, Regents of the University of California
+  *
+  * src/include/utils/pg_lsn.h
+  *
+  *-------------------------------------------------------------------------
+  */
+ #ifndef PG_LSN_H
+ #define PG_LSN_H
+ 
+ #include "fmgr.h"
+ 
+ extern Datum pg_lsn_in(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_out(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_recv(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_send(PG_FUNCTION_ARGS);
+ 
+ extern Datum pg_lsn_eq(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_ne(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_lt(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_gt(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_le(PG_FUNCTION_ARGS);
+ extern Datum pg_lsn_ge(PG_FUNCTION_ARGS);
+ 
+ extern Datum pg_lsn_mi(PG_FUNCTION_ARGS);
+ 
+ #endif   /* PG_LSN_H */
*** /dev/null
--- b/src/test/regress/expected/pg_lsn.out
***************
*** 0 ****
--- 1,62 ----
+ --
+ -- PG_LSN
+ --
+ CREATE TABLE PG_LSN_TBL (f1 pg_lsn);
+ -- Largest and smallest input
+ INSERT INTO PG_LSN_TBL VALUES ('0/0');
+ INSERT INTO PG_LSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ -- Incorrect input
+ INSERT INTO PG_LSN_TBL VALUES ('G/0');
+ ERROR:  invalid input syntax for transaction log location: "G/0"
+ LINE 1: INSERT INTO PG_LSN_TBL VALUES ('G/0');
+                                       ^
+ INSERT INTO PG_LSN_TBL VALUES ('-1/0');
+ ERROR:  invalid input syntax for transaction log location: "-1/0"
+ LINE 1: INSERT INTO PG_LSN_TBL VALUES ('-1/0');
+                                       ^
+ INSERT INTO PG_LSN_TBL VALUES (' 0/12345678');
+ ERROR:  invalid input syntax for transaction log location: " 0/12345678"
+ LINE 1: INSERT INTO PG_LSN_TBL VALUES (' 0/12345678');
+                                       ^
+ INSERT INTO PG_LSN_TBL VALUES ('ABCD/');
+ ERROR:  invalid input syntax for transaction log location: "ABCD/"
+ LINE 1: INSERT INTO PG_LSN_TBL VALUES ('ABCD/');
+                                       ^
+ INSERT INTO PG_LSN_TBL VALUES ('/ABCD');
+ ERROR:  invalid input syntax for transaction log location: "/ABCD"
+ LINE 1: INSERT INTO PG_LSN_TBL VALUES ('/ABCD');
+                                       ^
+ DROP TABLE PG_LSN_TBL;
+ -- Operators
+ SELECT pg_lsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+  pg_lsn_eq 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pg_lsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+  pg_lsn_ne 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pg_lsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+  pg_lsn_lt 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pg_lsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+  pg_lsn_gt 
+ ----------
+  t
+ (1 row)
+ 
+ SELECT pg_lsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ ERROR:  transaction log location out of range
+ SELECT pg_lsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct
+  pg_lsn_mi 
+ ----------
+         1
+ (1 row)
+ 
*** a/src/test/regress/parallel_schedule
--- b/src/test/regress/parallel_schedule
***************
*** 13,19 **** test: tablespace
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes
  
  # Depends on things setup during char, varchar and text
  test: strings
--- 13,19 ----
  # ----------
  # The first group of parallel tests
  # ----------
! test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric txid uuid enum money rangetypes pg_lsn
  
  # Depends on things setup during char, varchar and text
  test: strings
*** a/src/test/regress/serial_schedule
--- b/src/test/regress/serial_schedule
***************
*** 19,24 **** test: uuid
--- 19,25 ----
  test: enum
  test: money
  test: rangetypes
+ test: pg_lsn
  test: strings
  test: numerology
  test: point
*** /dev/null
--- b/src/test/regress/sql/pg_lsn.sql
***************
*** 0 ****
--- 1,25 ----
+ --
+ -- PG_LSN
+ --
+ 
+ CREATE TABLE PG_LSN_TBL (f1 pg_lsn);
+ 
+ -- Largest and smallest input
+ INSERT INTO PG_LSN_TBL VALUES ('0/0');
+ INSERT INTO PG_LSN_TBL VALUES ('FFFFFFFF/FFFFFFFF');
+ 
+ -- Incorrect input
+ INSERT INTO PG_LSN_TBL VALUES ('G/0');
+ INSERT INTO PG_LSN_TBL VALUES ('-1/0');
+ INSERT INTO PG_LSN_TBL VALUES (' 0/12345678');
+ INSERT INTO PG_LSN_TBL VALUES ('ABCD/');
+ INSERT INTO PG_LSN_TBL VALUES ('/ABCD');
+ DROP TABLE PG_LSN_TBL;
+ 
+ -- Operators
+ SELECT pg_lsn_eq('0/16AE7F8', '0/16AE7F8'); -- true
+ SELECT pg_lsn_ne('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT pg_lsn_lt('0/16AE7F7', '0/16AE7F8'); -- true
+ SELECT pg_lsn_gt('0/16AE7F8', '0/16AE7F7'); -- true
+ SELECT pg_lsn_mi('0/16AE7F7', '0/16AE7F8'); -- No negative results
+ SELECT pg_lsn_mi('0/16AE7F8', '0/16AE7F7'); -- correct

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index dca24fc..908f947 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -5244,7 +5244,7 @@
 
      <row>
       <entry><structfield>restart_lsn</structfield></entry>
-      <entry><type>text</type></entry>
+      <entry><type>pg_lsn</type></entry>
       <entry></entry>
       <entry>The address (<literal>LSN</literal>) of oldest WAL which still
       might be required by the consumer of this slot and thus won't be
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be548d7..a639662 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -15884,35 +15884,35 @@ SELECT set_config('log_statement_stats', 'off', false);
        <entry>
         <literal><function>pg_create_restore_point(<parameter>name</> <type>text</>)</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Create a named point for performing restore (restricted to superusers)</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_current_xlog_insert_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Get current transaction log insert location</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_current_xlog_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Get current transaction log write location</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_start_backup(<parameter>label</> <type>text</> <optional>, <parameter>fast</> <type>boolean</> </optional>)</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Prepare for performing on-line backup (restricted to superusers or replication roles)</entry>
       </row>
       <row>
        <entry>
         <literal><function>pg_stop_backup()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Finish performing on-line backup (restricted to superusers or replication roles)</entry>
       </row>
       <row>
@@ -15933,26 +15933,26 @@ SELECT set_config('log_statement_stats', 'off', false);
        <entry>
         <literal><function>pg_switch_xlog()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Force switch to a new transaction log file (restricted to superusers)</entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_xlogfile_name(<parameter>location</> <type>text</>)</function></literal>
+        <literal><function>pg_xlogfile_name(<parameter>location</> <type>pg_lsn</>)</function></literal>
         </entry>
        <entry><type>text</type></entry>
        <entry>Convert transaction log location string to file name</entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_xlogfile_name_offset(<parameter>location</> <type>text</>)</function></literal>
+        <literal><function>pg_xlogfile_name_offset(<parameter>location</> <type>pg_lsn</>)</function></literal>
         </entry>
        <entry><type>text</>, <type>integer</></entry>
        <entry>Convert transaction log location string to file name and decimal byte offset within file</entry>
       </row>
       <row>
        <entry>
-        <literal><function>pg_xlog_location_diff(<parameter>location</> <type>text</>, <parameter>location</> <type>text</>)</function></literal>
+        <literal><function>pg_xlog_location_diff(<parameter>location</> <type>pg_lsn</>, <parameter>location</> <type>pg_lsn</>)</function></literal>
        </entry>
        <entry><type>numeric</></entry>
        <entry>Calculate the difference between two transaction log locations</entry>
@@ -16107,7 +16107,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
        <entry>
         <literal><function>pg_last_xlog_receive_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Get last transaction log location received and synced to disk by
         streaming replication. While streaming replication is in progress
         this will increase monotonically. If recovery has completed this will
@@ -16121,7 +16121,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
        <entry>
         <literal><function>pg_last_xlog_replay_location()</function></literal>
         </entry>
-       <entry><type>text</type></entry>
+       <entry><type>pg_lsn</type></entry>
        <entry>Get last transaction log location replayed during recovery.
         If recovery is still in progress this will increase monotonically.
         If recovery has completed then this value will remain static at
@@ -16335,7 +16335,7 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
         <literal><function>pg_create_physical_replication_slot(<parameter>slotname</parameter> <type>text</type>, <parameter>plugin</parameter> <type>text</type>)</function></literal>
        </entry>
        <entry>
-        (<parameter>slotname</parameter> <type>text</type>, <parameter>xlog_position</parameter> <type>text</type>)
+        (<parameter>slotname</parameter> <type>text</type>, <parameter>xlog_position</parameter> <type>pg_lsn</type>)
        </entry>
        <entry>
         Creates a new physical replication slot named
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index 9133179..058f9a2 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -33,8 +33,6 @@
 #include "utils/timestamp.h"
 #include "storage/fd.h"
 
-static void validate_xlog_location(char *str);
-
 
 /*
  * pg_start_backup: set up for taking an on-line backup dump
@@ -52,7 +50,6 @@ pg_start_backup(PG_FUNCTION_ARGS)
 	bool		fast = PG_GETARG_BOOL(1);
 	char	   *backupidstr;
 	XLogRecPtr	startpoint;
-	char		startxlogstr[MAXFNAMELEN];
 
 	backupidstr = text_to_cstring(backupid);
 
@@ -63,9 +60,7 @@ pg_start_backup(PG_FUNCTION_ARGS)
 
 	startpoint = do_pg_start_backup(backupidstr, fast, NULL, NULL);
 
-	snprintf(startxlogstr, sizeof(startxlogstr), "%X/%X",
-			 (uint32) (startpoint >> 32), (uint32) startpoint);
-	PG_RETURN_TEXT_P(cstring_to_text(startxlogstr));
+	PG_RETURN_PG_LSN(startpoint);
 }
 
 /*
@@ -85,7 +80,6 @@ Datum
 pg_stop_backup(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	stoppoint;
-	char		stopxlogstr[MAXFNAMELEN];
 
 	if (!superuser() && !has_rolreplication(GetUserId()))
 		ereport(ERROR,
@@ -94,9 +88,7 @@ pg_stop_backup(PG_FUNCTION_ARGS)
 
 	stoppoint = do_pg_stop_backup(NULL, true, NULL);
 
-	snprintf(stopxlogstr, sizeof(stopxlogstr), "%X/%X",
-			 (uint32) (stoppoint >> 32), (uint32) stoppoint);
-	PG_RETURN_TEXT_P(cstring_to_text(stopxlogstr));
+	PG_RETURN_PG_LSN(stoppoint);
 }
 
 /*
@@ -124,9 +116,7 @@ pg_switch_xlog(PG_FUNCTION_ARGS)
 	/*
 	 * As a convenience, return the WAL location of the switch record
 	 */
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (switchpoint >> 32), (uint32) switchpoint);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PG_LSN(switchpoint);
 }
 
 /*
@@ -169,9 +159,7 @@ pg_create_restore_point(PG_FUNCTION_ARGS)
 	/*
 	 * As a convenience, return the WAL location of the restore point record
 	 */
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (restorepoint >> 32), (uint32) restorepoint);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PG_LSN(restorepoint);
 }
 
 /*
@@ -185,7 +173,6 @@ Datum
 pg_current_xlog_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	current_recptr;
-	char		location[MAXFNAMELEN];
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -195,9 +182,7 @@ pg_current_xlog_location(PG_FUNCTION_ARGS)
 
 	current_recptr = GetXLogWriteRecPtr();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (current_recptr >> 32), (uint32) current_recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PG_LSN(current_recptr);
 }
 
 /*
@@ -209,7 +194,6 @@ Datum
 pg_current_xlog_insert_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	current_recptr;
-	char		location[MAXFNAMELEN];
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -219,9 +203,7 @@ pg_current_xlog_insert_location(PG_FUNCTION_ARGS)
 
 	current_recptr = GetXLogInsertRecPtr();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (current_recptr >> 32), (uint32) current_recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PG_LSN(current_recptr);
 }
 
 /*
@@ -234,16 +216,13 @@ Datum
 pg_last_xlog_receive_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	recptr;
-	char		location[MAXFNAMELEN];
 
 	recptr = GetWalRcvWriteRecPtr(NULL, NULL);
 
 	if (recptr == 0)
 		PG_RETURN_NULL();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (recptr >> 32), (uint32) recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PG_LSN(recptr);
 }
 
 /*
@@ -256,16 +235,13 @@ Datum
 pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
 {
 	XLogRecPtr	recptr;
-	char		location[MAXFNAMELEN];
 
 	recptr = GetXLogReplayRecPtr(NULL);
 
 	if (recptr == 0)
 		PG_RETURN_NULL();
 
-	snprintf(location, sizeof(location), "%X/%X",
-			 (uint32) (recptr >> 32), (uint32) recptr);
-	PG_RETURN_TEXT_P(cstring_to_text(location));
+	PG_RETURN_PG_LSN(recptr);
 }
 
 /*
@@ -279,13 +255,11 @@ pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
 Datum
 pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
 {
-	text	   *location = PG_GETARG_TEXT_P(0);
-	char	   *locationstr;
 	uint32		hi,
 				lo;
 	XLogSegNo	xlogsegno;
 	uint32		xrecoff;
-	XLogRecPtr	locationpoint;
+	XLogRecPtr	locationpoint = PG_GETARG_PG_LSN(0);
 	char		xlogfilename[MAXFNAMELEN];
 	Datum		values[2];
 	bool		isnull[2];
@@ -300,20 +274,6 @@ pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
 				 errhint("pg_xlogfile_name_offset() cannot be executed during recovery.")));
 
 	/*
-	 * Read input and parse
-	 */
-	locationstr = text_to_cstring(location);
-
-	validate_xlog_location(locationstr);
-
-	if (sscanf(locationstr, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("could not parse transaction log location \"%s\"",
-						locationstr)));
-	locationpoint = ((uint64) hi) << 32 | lo;
-
-	/*
 	 * Construct a tuple descriptor for the result row.  This must match this
 	 * function's pg_proc entry!
 	 */
@@ -359,12 +319,10 @@ pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
 Datum
 pg_xlogfile_name(PG_FUNCTION_ARGS)
 {
-	text	   *location = PG_GETARG_TEXT_P(0);
-	char	   *locationstr;
 	uint32		hi,
 				lo;
 	XLogSegNo	xlogsegno;
-	XLogRecPtr	locationpoint;
+	XLogRecPtr	locationpoint = PG_GETARG_PG_LSN(0);
 	char		xlogfilename[MAXFNAMELEN];
 
 	if (RecoveryInProgress())
@@ -373,17 +331,6 @@ pg_xlogfile_name(PG_FUNCTION_ARGS)
 				 errmsg("recovery is in progress"),
 		 errhint("pg_xlogfile_name() cannot be executed during recovery.")));
 
-	locationstr = text_to_cstring(location);
-
-	validate_xlog_location(locationstr);
-
-	if (sscanf(locationstr, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("could not parse transaction log location \"%s\"",
-						locationstr)));
-	locationpoint = ((uint64) hi) << 32 | lo;
-
 	XLByteToPrevSeg(locationpoint, xlogsegno);
 	XLogFileName(xlogfilename, ThisTimeLineID, xlogsegno);
 
@@ -482,77 +429,27 @@ pg_is_in_recovery(PG_FUNCTION_ARGS)
 }
 
 /*
- * Validate the text form of a transaction log location.
- * (Just using sscanf() input allows incorrect values such as
- * negatives, so we have to be a bit more careful about that).
- */
-static void
-validate_xlog_location(char *str)
-{
-#define MAXLSNCOMPONENT		8
-
-	int			len1,
-				len2;
-
-	len1 = strspn(str, "0123456789abcdefABCDEF");
-	if (len1 < 1 || len1 > MAXLSNCOMPONENT || str[len1] != '/')
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
-
-	len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
-	if (len2 < 1 || len2 > MAXLSNCOMPONENT || str[len1 + 1 + len2] != '\0')
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-				 errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
-}
-
-/*
  * Compute the difference in bytes between two WAL locations.
  */
 Datum
 pg_xlog_location_diff(PG_FUNCTION_ARGS)
 {
-	text	   *location1 = PG_GETARG_TEXT_P(0);
-	text	   *location2 = PG_GETARG_TEXT_P(1);
-	char	   *str1,
-			   *str2;
-	XLogRecPtr	loc1,
-				loc2;
+	XLogRecPtr	loc1 = PG_GETARG_PG_LSN(0);
+	XLogRecPtr	loc2 = PG_GETARG_PG_LSN(1);
 	Numeric		result;
 	uint64		bytes1,
 				bytes2;
 	uint32		hi,
 				lo;
 
-	/*
-	 * Read and parse input
-	 */
-	str1 = text_to_cstring(location1);
-	str2 = text_to_cstring(location2);
-
-	validate_xlog_location(str1);
-	validate_xlog_location(str2);
-
-	if (sscanf(str1, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-		   errmsg("could not parse transaction log location \"%s\"", str1)));
-	loc1 = ((uint64) hi) << 32 | lo;
-
-	if (sscanf(str2, "%X/%X", &hi, &lo) != 2)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-		   errmsg("could not parse transaction log location \"%s\"", str2)));
-	loc2 = ((uint64) hi) << 32 | lo;
-
 	bytes1 = (uint64) loc1;
 	bytes2 = (uint64) loc2;
 
 	/*
 	 * result = bytes1 - bytes2.
 	 *
-	 * XXX: this won't handle values higher than 2^63 correctly.
+	 * XXX: this won't handle values higher than 2^63 correctly and can
+	 * return negative values.
 	 */
 	result = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
 			DirectFunctionCall1(int8_numeric, Int64GetDatum((int64) bytes1)),
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index f02efec..a7c6a4e 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -810,7 +810,7 @@ COMMENT ON FUNCTION ts_debug(text) IS
 
 CREATE OR REPLACE FUNCTION
   pg_start_backup(label text, fast boolean DEFAULT false)
-  RETURNS text STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
+  RETURNS pg_lsn STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
 
 CREATE OR REPLACE FUNCTION
   json_populate_record(base anyelement, from_json json, use_json_as_text boolean DEFAULT false)
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index 98a860e..fd26948 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -141,8 +141,6 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
 		bool		active;
 		Oid			database;
 		const char *slot_name;
-
-		char		restart_lsn_s[MAXFNAMELEN];
 		int			i;
 
 		SpinLockAcquire(&slot->mutex);
@@ -164,9 +162,6 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
 
 		memset(nulls, 0, sizeof(nulls));
 
-		snprintf(restart_lsn_s, sizeof(restart_lsn_s), "%X/%X",
-				 (uint32) (restart_lsn >> 32), (uint32) restart_lsn);
-
 		i = 0;
 		values[i++] = CStringGetTextDatum(slot_name);
 		if (database == InvalidOid)
@@ -180,7 +175,7 @@ pg_get_replication_slots(PG_FUNCTION_ARGS)
 		else
 			nulls[i++] = true;
 		if (restart_lsn != InvalidTransactionId)
-			values[i++] = CStringGetTextDatum(restart_lsn_s);
+			values[i++] = PgLsnGetDatum(restart_lsn);
 		else
 			nulls[i++] = true;
 
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ac72646..11c1e1a 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2971,28 +2971,28 @@ DATA(insert OID = 2171 ( pg_cancel_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v
 DESCR("cancel a server process' current query");
 DATA(insert OID = 2096 ( pg_terminate_backend		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 16 "23" _null_ _null_ _null_ _null_ pg_terminate_backend _null_ _null_ _null_ ));
 DESCR("terminate a server process");
-DATA(insert OID = 2172 ( pg_start_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 25 "25 16" _null_ _null_ _null_ _null_ pg_start_backup _null_ _null_ _null_ ));
+DATA(insert OID = 2172 ( pg_start_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 2 0 3220 "25 16" _null_ _null_ _null_ _null_ pg_start_backup _null_ _null_ _null_ ));
 DESCR("prepare for taking an online backup");
-DATA(insert OID = 2173 ( pg_stop_backup			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_stop_backup _null_ _null_ _null_ ));
+DATA(insert OID = 2173 ( pg_stop_backup			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_stop_backup _null_ _null_ _null_ ));
 DESCR("finish taking an online backup");
 DATA(insert OID = 3813 ( pg_is_in_backup		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_backup _null_ _null_ _null_ ));
 DESCR("true if server is in online backup");
 DATA(insert OID = 3814 ( pg_backup_start_time		PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_ pg_backup_start_time _null_ _null_ _null_ ));
 DESCR("start time of an online backup");
-DATA(insert OID = 2848 ( pg_switch_xlog			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_switch_xlog _null_ _null_ _null_ ));
+DATA(insert OID = 2848 ( pg_switch_xlog			PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_switch_xlog _null_ _null_ _null_ ));
 DESCR("switch to new xlog file");
-DATA(insert OID = 3098 ( pg_create_restore_point	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 25 "25" _null_ _null_ _null_ _null_ pg_create_restore_point _null_ _null_ _null_ ));
+DATA(insert OID = 3098 ( pg_create_restore_point	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 3220 "25" _null_ _null_ _null_ _null_ pg_create_restore_point _null_ _null_ _null_ ));
 DESCR("create a named restore point");
-DATA(insert OID = 2849 ( pg_current_xlog_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_current_xlog_location _null_ _null_ _null_ ));
+DATA(insert OID = 2849 ( pg_current_xlog_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_current_xlog_location _null_ _null_ _null_ ));
 DESCR("current xlog write location");
-DATA(insert OID = 2852 ( pg_current_xlog_insert_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
+DATA(insert OID = 2852 ( pg_current_xlog_insert_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_current_xlog_insert_location _null_ _null_ _null_ ));
 DESCR("current xlog insert location");
-DATA(insert OID = 2850 ( pg_xlogfile_name_offset	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2249 "25" "{25,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
+DATA(insert OID = 2850 ( pg_xlogfile_name_offset	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2249 "3220" "{3220,25,23}" "{i,o,o}" "{wal_location,file_name,file_offset}" _null_ pg_xlogfile_name_offset _null_ _null_ _null_ ));
 DESCR("xlog filename and byte offset, given an xlog location");
-DATA(insert OID = 2851 ( pg_xlogfile_name			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
+DATA(insert OID = 2851 ( pg_xlogfile_name			PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "3220" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
 DESCR("xlog filename, given an xlog location");
 
-DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "25 25" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
+DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
 DESCR("difference in bytes, given two xlog locations");
 
 DATA(insert OID = 3809 ( pg_export_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
@@ -3001,9 +3001,9 @@ DESCR("export a snapshot");
 DATA(insert OID = 3810 (  pg_is_in_recovery		PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 16 "" _null_ _null_ _null_ _null_ pg_is_in_recovery _null_ _null_ _null_ ));
 DESCR("true if server is in recovery");
 
-DATA(insert OID = 3820 ( pg_last_xlog_receive_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_last_xlog_receive_location _null_ _null_ _null_ ));
+DATA(insert OID = 3820 ( pg_last_xlog_receive_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_last_xlog_receive_location _null_ _null_ _null_ ));
 DESCR("current xlog flush location");
-DATA(insert OID = 3821 ( pg_last_xlog_replay_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_last_xlog_replay_location _null_ _null_ _null_ ));
+DATA(insert OID = 3821 ( pg_last_xlog_replay_location	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 3220 "" _null_ _null_ _null_ _null_ pg_last_xlog_replay_location _null_ _null_ _null_ ));
 DESCR("last xlog replay location");
 DATA(insert OID = 3830 ( pg_last_xact_replay_timestamp	PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 1184 "" _null_ _null_ _null_ _null_ pg_last_xact_replay_timestamp _null_ _null_ _null_ ));
 DESCR("timestamp of last replay xact");
@@ -4800,11 +4800,11 @@ DATA(insert OID = 3473 (  spg_range_quad_leaf_consistent	PGNSP PGUID 12 1 0 0 0
 DESCR("SP-GiST support for quad tree over range");
 
 /* replication slots */
-DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2249 "19" "{19,25,25}" "{i,o,o}" "{slotname,slotname,xlog_position}" _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
+DATA(insert OID = 3779 (  pg_create_physical_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2249 "19" "{19,25,3220}" "{i,o,o}" "{slotname,slotname,xlog_position}" _null_ pg_create_physical_replication_slot _null_ _null_ _null_ ));
 DESCR("create a physical replication slot");
 DATA(insert OID = 3780 (  pg_drop_replication_slot PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "19" _null_ _null_ _null_ _null_ pg_drop_replication_slot _null_ _null_ _null_ ));
 DESCR("drop a replication slot");
-DATA(insert OID = 3781 (  pg_get_replication_slots	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{25,25,26,16,28,25}" "{o,o,o,o,o,o}" "{slot_name,slot_type,datoid,active,xmin,restart_lsn}" _null_ pg_get_replication_slots _null_ _null_ _null_ ));
+DATA(insert OID = 3781 (  pg_get_replication_slots	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{25,25,26,16,28,3220}" "{o,o,o,o,o,o}" "{slot_name,slot_type,datoid,active,xmin,restart_lsn}" _null_ pg_get_replication_slots _null_ _null_ _null_ ));
 DESCR("information about replication slots currently in use");
 
 /* event triggers */

diff --git a/src/backend/utils/adt/pg_lsn.c b/src/backend/utils/adt/pg_lsn.c
index e2b528a..fae12e1 100644
--- a/src/backend/utils/adt/pg_lsn.c
+++ b/src/backend/utils/adt/pg_lsn.c
@@ -19,7 +19,7 @@
 #include "utils/pg_lsn.h"
 
 #define MAXPG_LSNLEN			17
-#define MAXPG_LSNCOMPONENT	8
+#define MAXPG_LSNCOMPONENT		8
 
 /*----------------------------------------------------------
  * Formatting and conversion routines.
diff --git a/src/test/regress/expected/pg_lsn.out b/src/test/regress/expected/pg_lsn.out
index 01d2983..504768c 100644
--- a/src/test/regress/expected/pg_lsn.out
+++ b/src/test/regress/expected/pg_lsn.out
@@ -52,13 +52,13 @@ SELECT '0/16AE7F8' > pg_lsn '0/16AE7F7';
  t
 (1 row)
 
-SELECT '0/16AE7F7'::pg_lsn - '0/16AE7F8'::pg_lsn; -- No negative results
+SELECT '0/16AE7F7'::pg_lsn - '0/16AE7F8'::pg_lsn;
  ?column? 
 ----------
        -1
 (1 row)
 
-SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn; -- correct
+SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn;
  ?column? 
 ----------
         1
diff --git a/src/test/regress/sql/pg_lsn.sql b/src/test/regress/sql/pg_lsn.sql
index dddafb3..1634d37 100644
--- a/src/test/regress/sql/pg_lsn.sql
+++ b/src/test/regress/sql/pg_lsn.sql
@@ -21,5 +21,5 @@ SELECT '0/16AE7F8' = '0/16AE7F8'::pg_lsn;
 SELECT '0/16AE7F8'::pg_lsn != '0/16AE7F7';
 SELECT '0/16AE7F7' < '0/16AE7F8'::pg_lsn;
 SELECT '0/16AE7F8' > pg_lsn '0/16AE7F7';
-SELECT '0/16AE7F7'::pg_lsn - '0/16AE7F8'::pg_lsn; -- No negative results
-SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn; -- correct
+SELECT '0/16AE7F7'::pg_lsn - '0/16AE7F8'::pg_lsn;
+SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn;

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index a37e6b6..370857a 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -1490,24 +1490,24 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
     </row>
     <row>
      <entry><structfield>sent_location</></entry>
-     <entry><type>text</></entry>
+     <entry><type>pg_lsn</></entry>
      <entry>Last transaction log position sent on this connection</entry>
     </row>
     <row>
      <entry><structfield>write_location</></entry>
-     <entry><type>text</></entry>
+     <entry><type>pg_lsn</></entry>
      <entry>Last transaction log position written to disk by this standby
       server</entry>
     </row>
     <row>
      <entry><structfield>flush_location</></entry>
-     <entry><type>text</></entry>
+     <entry><type>pg_lsn</></entry>
      <entry>Last transaction log position flushed to disk by this standby
       server</entry>
     </row>
     <row>
      <entry><structfield>replay_location</></entry>
-     <entry><type>text</></entry>
+     <entry><type>pg_lsn</></entry>
      <entry>Last transaction log position replayed into the database on this
       standby server</entry>
     </row>
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 06b22e2..048367a 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -67,6 +67,7 @@
 #include "utils/builtins.h"
 #include "utils/guc.h"
 #include "utils/memutils.h"
+#include "utils/pg_lsn.h"
 #include "utils/ps_status.h"
 #include "utils/resowner.h"
 #include "utils/timeout.h"
@@ -2137,7 +2138,6 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 	{
 		/* use volatile pointer to prevent code rearrangement */
 		volatile WalSnd *walsnd = &WalSndCtl->walsnds[i];
-		char		location[MAXFNAMELEN];
 		XLogRecPtr	sentPtr;
 		XLogRecPtr	write;
 		XLogRecPtr	flush;
@@ -2171,28 +2171,19 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 		else
 		{
 			values[1] = CStringGetTextDatum(WalSndGetStateString(state));
-
-			snprintf(location, sizeof(location), "%X/%X",
-					 (uint32) (sentPtr >> 32), (uint32) sentPtr);
-			values[2] = CStringGetTextDatum(location);
+			values[2] = LSNGetDatum(sentPtr);
 
 			if (write == 0)
 				nulls[3] = true;
-			snprintf(location, sizeof(location), "%X/%X",
-					 (uint32) (write >> 32), (uint32) write);
-			values[3] = CStringGetTextDatum(location);
+			values[3] = LSNGetDatum(write);
 
 			if (flush == 0)
 				nulls[4] = true;
-			snprintf(location, sizeof(location), "%X/%X",
-					 (uint32) (flush >> 32), (uint32) flush);
-			values[4] = CStringGetTextDatum(location);
+			values[4] = LSNGetDatum(flush);
 
 			if (apply == 0)
 				nulls[5] = true;
-			snprintf(location, sizeof(location), "%X/%X",
-					 (uint32) (apply >> 32), (uint32) apply);
-			values[5] = CStringGetTextDatum(location);
+			values[5] = LSNGetDatum(apply);
 
 			values[6] = Int32GetDatum(sync_priority[i]);
 
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 11c1e1a..a2cc19f 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2634,7 +2634,7 @@ DATA(insert OID = 1936 (  pg_stat_get_backend_idset		PGNSP PGUID 12 1 100 0 0 f
 DESCR("statistics: currently active backend IDs");
 DATA(insert OID = 2022 (  pg_stat_get_activity			PGNSP PGUID 12 1 100 0 0 f f f f f t s 1 0 2249 "23" "{23,26,23,26,25,25,25,16,1184,1184,1184,1184,869,25,23}" "{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o}" "{pid,datid,pid,usesysid,application_name,state,query,waiting,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port}" _null_ pg_stat_get_activity _null_ _null_ _null_ ));
 DESCR("statistics: information about currently active backends");
-DATA(insert OID = 3099 (  pg_stat_get_wal_senders	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{23,25,25,25,25,25,23,25}" "{o,o,o,o,o,o,o,o}" "{pid,state,sent_location,write_location,flush_location,replay_location,sync_priority,sync_state}" _null_ pg_stat_get_wal_senders _null_ _null_ _null_ ));
+DATA(insert OID = 3099 (  pg_stat_get_wal_senders	PGNSP PGUID 12 1 10 0 0 f f f f f t s 0 0 2249 "" "{23,25,3220,3220,3220,3220,23,25}" "{o,o,o,o,o,o,o,o}" "{pid,state,sent_location,write_location,flush_location,replay_location,sync_priority,sync_state}" _null_ pg_stat_get_wal_senders _null_ _null_ _null_ ));
 DESCR("statistics: information about currently active replication");
 DATA(insert OID = 2026 (  pg_backend_pid				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_backend_pid _null_ _null_ _null_ ));
 DESCR("statistics: current backend PID");