Add btree and hash opclasses for pg_lsn.

This is needed to allow ORDER BY, DISTINCT, etc to work as expected for
pg_lsn values.

We had previously decided to put this off for 9.5, but in view of commit
eeca4cd3 there's no reason to avoid a
catversion bump for 9.4beta2, and this does make a pretty significant
usability difference for pg_lsn.

Michael Paquier, with fixes from Andres Freund and Tom Lane

src/backend/utils/adt/pg_lsn.c

 /*-------------------------------------------------------------------------
  *
  * pg_lsn.c
- *	  Internal PostgreSQL LSN operations
+ *	  Operations for the pg_lsn datatype.
  *
- * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
@@ -13,6 +13,7 @@
  */
 #include "postgres.h"
 
+#include "access/hash.h"
 #include "funcapi.h"
 #include "libpq/pqformat.h"
 #include "utils/builtins.h"
@@ -153,6 +154,29 @@ pg_lsn_ge(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(lsn1 >= lsn2);
 }
 
+/* btree index opclass support */
+Datum
+pg_lsn_cmp(PG_FUNCTION_ARGS)
+{
+	XLogRecPtr	a = PG_GETARG_LSN(0);
+	XLogRecPtr	b = PG_GETARG_LSN(1);
+
+	if (a > b)
+		PG_RETURN_INT32(1);
+	else if (a == b)
+		PG_RETURN_INT32(0);
+	else
+		PG_RETURN_INT32(-1);
+}
+
+/* hash index opclass support */
+Datum
+pg_lsn_hash(PG_FUNCTION_ARGS)
+{
+	/* We can use hashint8 directly */
+	return hashint8(fcinfo);
+}
+
 
 /*----------------------------------------------------------
  *	Arithmetic operators on PostgreSQL LSNs.

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201405111
+#define CATALOG_VERSION_NO	201406041
 
 #endif

src/include/catalog/pg_amop.h

@@ -512,6 +512,16 @@ DATA(insert (	2968  2950 2950 3 s 2972	403 0 ));
 DATA(insert (	2968  2950 2950 4 s 2977	403 0 ));
 DATA(insert (	2968  2950 2950 5 s 2975	403 0 ));
 
+/*
+ * btree pg_lsn_ops
+ */
+
+DATA(insert (	3253  3220 3220 1 s 3224	403 0 ));
+DATA(insert (	3253  3220 3220 2 s 3226	403 0 ));
+DATA(insert (	3253  3220 3220 3 s 3222	403 0 ));
+DATA(insert (	3253  3220 3220 4 s 3227	403 0 ));
+DATA(insert (	3253  3220 3220 5 s 3225	403 0 ));
+
 /*
  *	hash index _ops
  */
@@ -581,6 +591,8 @@ DATA(insert (	2231   1042 1042 1 s 1054 405 0 ));
 DATA(insert (	2235   1033 1033 1 s  974 405 0 ));
 /* uuid_ops */
 DATA(insert (	2969   2950 2950 1 s 2972 405 0 ));
+/* pg_lsn_ops */
+DATA(insert (	3254   3220 3220 1 s 3222 405 0 ));
 /* numeric_ops */
 DATA(insert (	1998   1700 1700 1 s 1752 405 0 ));
 /* array_ops */

src/include/catalog/pg_amproc.h

@@ -134,6 +134,7 @@ DATA(insert (	2789   27 27 1 2794 ));
 DATA(insert (	2968   2950 2950 1 2960 ));
 DATA(insert (	2994   2249 2249 1 2987 ));
 DATA(insert (	3194   2249 2249 1 3187 ));
+DATA(insert (	3253   3220 3220 1 3251 ));
 DATA(insert (	3522   3500 3500 1 3514 ));
 DATA(insert (	3626   3614 3614 1 3622 ));
 DATA(insert (	3683   3615 3615 1 3668 ));
@@ -174,6 +175,7 @@ DATA(insert (	2229   25 25 1 400 ));
 DATA(insert (	2231   1042 1042 1 1080 ));
 DATA(insert (	2235   1033 1033 1 329 ));
 DATA(insert (	2969   2950 2950 1 2963 ));
+DATA(insert (	3254   3220 3220 1 3252 ));
 DATA(insert (	3523   3500 3500 1 3515 ));
 DATA(insert (	3903   3831 3831 1 3902 ));
 DATA(insert (	4034   3802 3802 1 4045 ));

src/include/catalog/pg_opclass.h

@@ -215,6 +215,8 @@ DATA(insert (	2742	_reltime_ops		PGNSP PGUID 2745  1024 t 703 ));
 DATA(insert (	2742	_tinterval_ops		PGNSP PGUID 2745  1025 t 704 ));
 DATA(insert (	403		uuid_ops			PGNSP PGUID 2968  2950 t 0 ));
 DATA(insert (	405		uuid_ops			PGNSP PGUID 2969  2950 t 0 ));
+DATA(insert (	403		pg_lsn_ops			PGNSP PGUID 3253  3220 t 0 ));
+DATA(insert (	405		pg_lsn_ops			PGNSP PGUID 3254  3220 t 0 ));
 DATA(insert (	403		enum_ops			PGNSP PGUID 3522  3500 t 0 ));
 DATA(insert (	405		enum_ops			PGNSP PGUID 3523  3500 t 0 ));
 DATA(insert (	403		tsvector_ops		PGNSP PGUID 3626  3614 t 0 ));

src/include/catalog/pg_operator.h

@@ -1595,7 +1595,7 @@ DATA(insert OID = 2977 (  ">="	   PGNSP PGUID b f f 2950 2950 16 2976 2974 uuid_
 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 ));
+DATA(insert OID = 3222 (  "="	   PGNSP PGUID b t t 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");

src/include/catalog/pg_opfamily.h

@@ -134,6 +134,8 @@ DATA(insert OID = 1029 (	783		point_ops		PGNSP PGUID ));
 DATA(insert OID = 2745 (	2742	array_ops		PGNSP PGUID ));
 DATA(insert OID = 2968 (	403		uuid_ops		PGNSP PGUID ));
 DATA(insert OID = 2969 (	405		uuid_ops		PGNSP PGUID ));
+DATA(insert OID = 3253 (	403		pg_lsn_ops		PGNSP PGUID ));
+DATA(insert OID = 3254 (	405		pg_lsn_ops		PGNSP PGUID ));
 DATA(insert OID = 3522 (	403		enum_ops		PGNSP PGUID ));
 DATA(insert OID = 3523 (	405		enum_ops		PGNSP PGUID ));
 DATA(insert OID = 3626 (	403		tsvector_ops	PGNSP PGUID ));

src/include/catalog/pg_proc.h

@@ -4293,6 +4293,10 @@ DATA(insert OID = 3238 (  pg_lsn_recv	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 3
 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");
+DATA(insert OID = 3251 (  pg_lsn_cmp	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 23 "3220 3220" _null_ _null_ _null_ _null_ pg_lsn_cmp _null_ _null_ _null_ ));
+DESCR("less-equal-greater");
+DATA(insert OID = 3252 (  pg_lsn_hash	PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 23 "3220" _null_ _null_ _null_ _null_ pg_lsn_hash _null_ _null_ _null_ ));
+DESCR("hash");
 
 /* 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_ ));

src/include/utils/pg_lsn.h

@@ -29,6 +29,8 @@ 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_cmp(PG_FUNCTION_ARGS);
+extern Datum pg_lsn_hash(PG_FUNCTION_ARGS);
 
 extern Datum pg_lsn_mi(PG_FUNCTION_ARGS);
 

src/test/regress/expected/pg_lsn.out

@@ -64,3 +64,133 @@ SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn;
         1
 (1 row)
 
+-- Check btree and hash opclasses
+EXPLAIN (COSTS OFF)
+SELECT DISTINCT (i || '/' || j)::pg_lsn f
+  FROM generate_series(1, 10) i,
+       generate_series(1, 10) j,
+       generate_series(1, 5) k
+  ORDER BY f;
+                                QUERY PLAN                                
+--------------------------------------------------------------------------
+ Sort
+   Sort Key: (((((i.i)::text || '/'::text) || (j.j)::text))::pg_lsn)
+   ->  HashAggregate
+         Group Key: ((((i.i)::text || '/'::text) || (j.j)::text))::pg_lsn
+         ->  Nested Loop
+               ->  Function Scan on generate_series k
+               ->  Materialize
+                     ->  Nested Loop
+                           ->  Function Scan on generate_series i
+                           ->  Function Scan on generate_series j
+(10 rows)
+
+SELECT DISTINCT (i || '/' || j)::pg_lsn f
+  FROM generate_series(1, 10) i,
+       generate_series(1, 10) j,
+       generate_series(1, 5) k
+  ORDER BY f;
+   f   
+-------
+ 1/1
+ 1/2
+ 1/3
+ 1/4
+ 1/5
+ 1/6
+ 1/7
+ 1/8
+ 1/9
+ 1/10
+ 2/1
+ 2/2
+ 2/3
+ 2/4
+ 2/5
+ 2/6
+ 2/7
+ 2/8
+ 2/9
+ 2/10
+ 3/1
+ 3/2
+ 3/3
+ 3/4
+ 3/5
+ 3/6
+ 3/7
+ 3/8
+ 3/9
+ 3/10
+ 4/1
+ 4/2
+ 4/3
+ 4/4
+ 4/5
+ 4/6
+ 4/7
+ 4/8
+ 4/9
+ 4/10
+ 5/1
+ 5/2
+ 5/3
+ 5/4
+ 5/5
+ 5/6
+ 5/7
+ 5/8
+ 5/9
+ 5/10
+ 6/1
+ 6/2
+ 6/3
+ 6/4
+ 6/5
+ 6/6
+ 6/7
+ 6/8
+ 6/9
+ 6/10
+ 7/1
+ 7/2
+ 7/3
+ 7/4
+ 7/5
+ 7/6
+ 7/7
+ 7/8
+ 7/9
+ 7/10
+ 8/1
+ 8/2
+ 8/3
+ 8/4
+ 8/5
+ 8/6
+ 8/7
+ 8/8
+ 8/9
+ 8/10
+ 9/1
+ 9/2
+ 9/3
+ 9/4
+ 9/5
+ 9/6
+ 9/7
+ 9/8
+ 9/9
+ 9/10
+ 10/1
+ 10/2
+ 10/3
+ 10/4
+ 10/5
+ 10/6
+ 10/7
+ 10/8
+ 10/9
+ 10/10
+(100 rows)
+

src/test/regress/sql/pg_lsn.sql

@@ -23,3 +23,17 @@ SELECT '0/16AE7F7' < '0/16AE7F8'::pg_lsn;
 SELECT '0/16AE7F8' > pg_lsn '0/16AE7F7';
 SELECT '0/16AE7F7'::pg_lsn - '0/16AE7F8'::pg_lsn;
 SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn;
+
+-- Check btree and hash opclasses
+EXPLAIN (COSTS OFF)
+SELECT DISTINCT (i || '/' || j)::pg_lsn f
+  FROM generate_series(1, 10) i,
+       generate_series(1, 10) j,
+       generate_series(1, 5) k
+  ORDER BY f;
+
+SELECT DISTINCT (i || '/' || j)::pg_lsn f
+  FROM generate_series(1, 10) i,
+       generate_series(1, 10) j,
+       generate_series(1, 5) k
+  ORDER BY f;