convert to new txid interface apperaing in 8.3

16 files changed, 252 insertions, 111 deletions

diff --git a/python/londiste/installer.py b/python/londiste/installer.py
index c4e51b9d..e76cdb20 100644
--- a/python/londiste/installer.py
+++ b/python/londiste/installer.py
@@ -7,7 +7,7 @@ __all__ = ['install_provider', 'install_subscriber']
 
 provider_object_list = [
     skytools.DBLanguage("plpgsql"),
-    skytools.DBFunction('get_current_snapshot', 0, sql_file = "txid.sql"),
+    skytools.DBFunction('txid_current_snapshot', 0, sql_file = "txid.sql"),
     skytools.DBSchema('pgq', sql_file = "pgq.sql"),
     skytools.DBSchema('londiste', sql_file = "londiste.sql")
 ]
diff --git a/python/londiste/table_copy.py b/python/londiste/table_copy.py
index aa99e376..5e21483a 100644
--- a/python/londiste/table_copy.py
+++ b/python/londiste/table_copy.py
@@ -59,7 +59,7 @@ class CopyTable(Replicator):
         self.real_copy(src_curs, dst_curs, tbl_stat)
 
         # get snapshot
-        src_curs.execute("select get_current_snapshot()")
+        src_curs.execute("select txid_current_snapshot()")
         snapshot = src_curs.fetchone()[0]
         src_db.commit()
 
diff --git a/python/pgq/ticker.py b/python/pgq/ticker.py
index a9d6190c..bff59214 100644
--- a/python/pgq/ticker.py
+++ b/python/pgq/ticker.py
@@ -11,7 +11,7 @@ from maint import MaintenanceJob
 __all__ = ['SmartTicker']
 
 def is_txid_sane(curs):
-    curs.execute("select get_current_txid()")
+    curs.execute("select txid_current()")
     txid = curs.fetchone()[0]
 
     # on 8.2 theres no such table
diff --git a/python/pgqadm.py b/python/pgqadm.py
index e732bea0..07c7aa01 100755
--- a/python/pgqadm.py
+++ b/python/pgqadm.py
@@ -85,7 +85,7 @@ class PGQAdmin(skytools.DBScript):
     def installer(self):
         objs = [
             skytools.DBLanguage("plpgsql"),
-            skytools.DBFunction("get_current_txid", 0, sql_file="txid.sql"),
+            skytools.DBFunction("txid_current_snapshot", 0, sql_file="txid.sql"),
             skytools.DBSchema("pgq", sql_file="pgq.sql"),
         ]
 
diff --git a/sql/pgq/functions/pgq.batch_event_sql.sql b/sql/pgq/functions/pgq.batch_event_sql.sql
index 2c0588fe..043a3caa 100644
--- a/sql/pgq/functions/pgq.batch_event_sql.sql
+++ b/sql/pgq/functions/pgq.batch_event_sql.sql
@@ -19,8 +19,8 @@ returns text as $$
 --
 --      Simplest solution would be
 --      > WHERE ev_txid >= xmin1 AND ev_txid <= xmax2
---      >   AND NOT txid_in_snapshot(ev_txid, sn1)
---      >   AND txid_in_snapshot(ev_txid, sn2)
+--      >   AND NOT txid_visible_in_snapshot(ev_txid, sn1)
+--      >   AND txid_visible_in_snapshot(ev_txid, sn2)
 --
 --      The simple solution has a problem with long transactions (xmin1 very low).
 --      All the batches that happen when the long tx is active will need
@@ -48,8 +48,8 @@ declare
     batch           record;
 begin
     select s.sub_last_tick, s.sub_next_tick, s.sub_id, s.sub_queue,
-           get_snapshot_xmax(last.tick_snapshot) as tx_start,
-           get_snapshot_xmax(cur.tick_snapshot) as tx_end,
+           txid_snapshot_xmax(last.tick_snapshot) as tx_start,
+           txid_snapshot_xmax(cur.tick_snapshot) as tx_end,
            last.tick_snapshot as last_snapshot,
            cur.tick_snapshot as cur_snapshot
         into batch
@@ -68,8 +68,8 @@ begin
     for rec in
         -- active tx-es in prev_snapshot that were committed in cur_snapshot
         select id1 from
-            get_snapshot_active(batch.last_snapshot) id1 left join
-            get_snapshot_active(batch.cur_snapshot) id2 on (id1 = id2)
+            txid_snapshot_xip(batch.last_snapshot) id1 left join
+            txid_snapshot_xip(batch.cur_snapshot) id2 on (id1 = id2)
         where id2 is null
         order by 1 desc
     loop
@@ -107,8 +107,8 @@ begin
             || ' and last.tick_queue = ' || batch.sub_queue
             || ' and ev.ev_txid >= ' || batch.tx_start
             || ' and ev.ev_txid <= ' || batch.tx_end
-            || ' and txid_in_snapshot(ev.ev_txid, cur.tick_snapshot)'
-            || ' and not txid_in_snapshot(ev.ev_txid, last.tick_snapshot)'
+            || ' and txid_visible_in_snapshot(ev.ev_txid, cur.tick_snapshot)'
+            || ' and not txid_visible_in_snapshot(ev.ev_txid, last.tick_snapshot)'
             || retry_expr;
         -- now include older tx-es, that were ongoing
         -- at the time of prev_snapshot
diff --git a/sql/pgq/functions/pgq.batch_event_tables.sql b/sql/pgq/functions/pgq.batch_event_tables.sql
index f6bdc309..fd8cbd65 100644
--- a/sql/pgq/functions/pgq.batch_event_tables.sql
+++ b/sql/pgq/functions/pgq.batch_event_tables.sql
@@ -16,8 +16,8 @@ declare
     batch                 record;
 begin
     select
-           get_snapshot_xmin(last.tick_snapshot) as tx_min, -- absolute minimum
-           get_snapshot_xmax(cur.tick_snapshot) as tx_max, -- absolute maximum
+           txid_snapshot_xmin(last.tick_snapshot) as tx_min, -- absolute minimum
+           txid_snapshot_xmax(cur.tick_snapshot) as tx_max, -- absolute maximum
            q.queue_data_pfx, q.queue_ntables,
            q.queue_cur_table, q.queue_switch_step1, q.queue_switch_step2
         into batch
diff --git a/sql/pgq/functions/pgq.maint_rotate_tables.sql b/sql/pgq/functions/pgq.maint_rotate_tables.sql
index f9d12367..b52a5025 100644
--- a/sql/pgq/functions/pgq.maint_rotate_tables.sql
+++ b/sql/pgq/functions/pgq.maint_rotate_tables.sql
@@ -31,7 +31,7 @@ begin
     -- check if any consumer is on previous table
     select coalesce(count(*), 0) into badcnt
         from pgq.subscription, pgq.tick
-        where get_snapshot_xmin(tick_snapshot) < cf.queue_switch_step2
+        where txid_snapshot_xmin(tick_snapshot) < cf.queue_switch_step2
           and sub_queue = cf.queue_id
           and tick_queue = cf.queue_id
           and tick_id = (select tick_id from pgq.tick
@@ -65,14 +65,14 @@ begin
     update pgq.queue
         set queue_cur_table = nr,
             queue_switch_time = current_timestamp,
-            queue_switch_step1 = get_current_txid(),
+            queue_switch_step1 = txid_current(),
             queue_switch_step2 = NULL
         where queue_id = cf.queue_id;
 
     -- clean ticks - avoid partial batches
     delete from pgq.tick
         where tick_queue = cf.queue_id
-          and get_snapshot_xmin(tick_snapshot) < cf.queue_switch_step2;
+          and txid_snapshot_xmin(tick_snapshot) < cf.queue_switch_step2;
 
     return 1;
 end;
@@ -90,7 +90,7 @@ returns integer as $$
 -- tranaction than step1
 begin
     update pgq.queue
-       set queue_switch_step2 = get_current_txid()
+       set queue_switch_step2 = txid_current()
      where queue_switch_step2 is null;
     return 1;
 end;
diff --git a/sql/pgq/structure/tables.sql b/sql/pgq/structure/tables.sql
index 83e23d3b..57e749c1 100644
--- a/sql/pgq/structure/tables.sql
+++ b/sql/pgq/structure/tables.sql
@@ -73,8 +73,8 @@ create table pgq.queue (
         queue_ntables               integer     not null default 3,
         queue_cur_table             integer     not null default 0,
         queue_rotation_period       interval    not null default '2 hours',
-	queue_switch_step1          bigint      not null default get_current_txid(),
-	queue_switch_step2          bigint               default get_current_txid(),
+        queue_switch_step1          bigint      not null default txid_current(),
+        queue_switch_step2          bigint               default txid_current(),
         queue_switch_time           timestamptz not null default now(),
 
         queue_external_ticker       boolean     not null default false,
@@ -105,7 +105,7 @@ create table pgq.tick (
         tick_queue                  int4            not null,
         tick_id                     bigint          not null,
         tick_time                   timestamptz     not null default now(),
-        tick_snapshot               txid_snapshot   not null default get_current_snapshot(),
+        tick_snapshot               txid_snapshot   not null default txid_current_snapshot(),
 
 	constraint tick_pkey primary key (tick_queue, tick_id),
         constraint tick_queue_fkey foreign key (tick_queue)
@@ -173,7 +173,7 @@ create table pgq.event_template (
 	ev_id	            bigint          not null,
         ev_time             timestamptz     not null,
 
-        ev_txid             bigint          not null default get_current_txid(),
+        ev_txid             bigint          not null default txid_current(),
         ev_owner            int4,
         ev_retry            int4,
 
diff --git a/sql/txid/Makefile b/sql/txid/Makefile
index 64b2c106..d3e25b8f 100644
--- a/sql/txid/Makefile
+++ b/sql/txid/Makefile
@@ -1,30 +1,50 @@
 
+include ../../config.mak
+
+PGVER := $(shell $(PG_CONFIG) --version | sed 's/PostgreSQL //')
+
+ifeq ($(PGVER),)
+$(error skytools not configured, cannot continue)
+else
+# postgres >= manages epoch itself, so skip epoch tables
+pg83 = $(shell test $(PGVER) "<" "8.3" && echo "false" || echo "true")
+pg82 = $(shell test $(PGVER) "<" "8.2" && echo "false" || echo "true")
+endif
+
+ifeq ($(pg83),true)  # we have 8.3 with internal txid
+
+# nothing to do
+
+else # 8.2 or 8.1
+#
+# pg < 8.3 needs this module
+#
 MODULE_big = txid
 SRCS = txid.c epoch.c
 OBJS = $(SRCS:.c=.o)
-
-DATA_built = txid.sql
+REGRESS = txid
+REGRESS_OPTS = --load-language=plpgsql
 DATA = uninstall_txid.sql
 DOCS = README.txid
+DATA_built = txid.sql
 EXTRA_CLEAN = txid.sql.in
 
-REGRESS = txid
-REGRESS_OPTS = --load-language=plpgsql
+ifeq ($(pg82),true)
+# 8.2 tracks epoch internally
+TXID_SQL = txid.std.sql
+else
+# 8.1 needs epoch-tracking code
+TXID_SQL = txid.std.sql txid.schema.sql
+endif # ! 8.2
+endif # ! 8.3
 
-include ../../config.mak
+# PGXS build procedure
 include $(PGXS)
 
 # additional deps
 txid.o: txid.h
 epoch.o: txid.h
 
-# postgres >= manages epoch itself, so skip epoch tables
-pgnew = $(shell test $(VERSION) "<" "8.2" && echo "false" || echo "true")
-ifeq ($(pgnew),true)
-TXID_SQL = txid.std.sql
-else
-TXID_SQL = txid.std.sql txid.schema.sql
-endif
 txid.sql.in: $(TXID_SQL)
 	cat $(TXID_SQL) > $@
 
diff --git a/sql/txid/README.txid b/sql/txid/README.txid
index 6cdac28a..1a46a748 100644
--- a/sql/txid/README.txid
+++ b/sql/txid/README.txid
@@ -17,37 +17,33 @@ read-write access - ca. after 100k - 500k transactions.
 Also it contains type 'txid_snapshot' and following functions:
 
 
-get_current_txid() returns int8
+txid_current() returns int8
 
   Current transaction ID
 
-get_current_snapshot() returns txid_snapshot
+txid_current_snapshot() returns txid_snapshot
 
   Current snapshot
 
-get_snapshot_xmin( snap ) returns int8      -- 
+txid_snapshot_xmin( snap ) returns int8
 
   Smallest TXID in snapshot.  TXID's smaller than this
   are all visible in snapshot.
 
-get_snapshot_xmax( snap ) returns int8
+txid_snapshot_xmax( snap ) returns int8
 
   Largest TXID in snapshot.  TXID's starting from this one are
   all invisible in snapshot.
 	
-get_snapshot_values( snap ) setof int8
+txid_snapshot_xip( snap ) setof int8
 
   List of uncommitted TXID's in snapshot, that are invisible
   in snapshot.  Values are between xmin and xmax.
 
-txid_in_snapshot(id, snap) returns bool
+txid_visible_in_snapshot(id, snap) returns bool
 
   Is TXID visible in snapshot?
 
-txid_not_in_snapshot(id, snap) returns bool
-
-  Is TXID invisible in snapshot?
-
 
 Problems
 --------
diff --git a/sql/txid/expected/txid.out b/sql/txid/expected/txid.out
index 400f88c2..7b394449 100644
--- a/sql/txid/expected/txid.out
+++ b/sql/txid/expected/txid.out
@@ -33,56 +33,45 @@ select snap from snapshot_test order by nr;
  100001:100009:100005,100007,100008
 (3 rows)
 
-select  get_snapshot_xmin(snap),
-	get_snapshot_xmax(snap),
-	get_snapshot_active(snap)
+select  txid_snapshot_xmin(snap),
+	txid_snapshot_xmax(snap),
+	txid_snapshot_xip(snap)
 from snapshot_test order by nr;
- get_snapshot_xmin | get_snapshot_xmax | get_snapshot_active 
--------------------+-------------------+---------------------
-                12 |                20 |                  13
-                12 |                20 |                  15
-                12 |                20 |                  18
-            100001 |            100009 |              100005
-            100001 |            100009 |              100007
-            100001 |            100009 |              100008
+ txid_snapshot_xmin | txid_snapshot_xmax | txid_snapshot_xip 
+--------------------+--------------------+-------------------
+                 12 |                 20 |                13
+                 12 |                 20 |                15
+                 12 |                 20 |                18
+             100001 |             100009 |            100005
+             100001 |             100009 |            100007
+             100001 |             100009 |            100008
 (6 rows)
 
-select id, txid_in_snapshot(id, snap),
-       txid_not_in_snapshot(id, snap)
+select id, txid_visible_in_snapshot(id, snap)
 from snapshot_test, generate_series(11, 21) id
 where nr = 2;
- id | txid_in_snapshot | txid_not_in_snapshot 
-----+------------------+----------------------
- 11 | t                | f
- 12 | t                | f
- 13 | f                | t
- 14 | t                | f
- 15 | f                | t
- 16 | t                | f
- 17 | t                | f
- 18 | f                | t
- 19 | t                | f
- 20 | f                | t
- 21 | f                | t
+ id | txid_visible_in_snapshot 
+----+--------------------------
+ 11 | t
+ 12 | t
+ 13 | f
+ 14 | t
+ 15 | f
+ 16 | t
+ 17 | t
+ 18 | f
+ 19 | t
+ 20 | f
+ 21 | f
 (11 rows)
 
 -- test current values also
-select get_current_txid() >= get_snapshot_xmin(get_current_snapshot());
+select txid_current() >= txid_snapshot_xmin(txid_current_snapshot());
  ?column? 
 ----------
  t
 (1 row)
 
-select get_current_txid() < get_snapshot_xmax(get_current_snapshot());
- ?column? 
-----------
- t
-(1 row)
-
-select txid_in_snapshot(get_current_txid(), get_current_snapshot()),
-   txid_not_in_snapshot(get_current_txid(), get_current_snapshot());
- txid_in_snapshot | txid_not_in_snapshot 
-------------------+----------------------
- t                | f
-(1 row)
-
+-- select txid_current_txid() < txid_snapshot_xmax(txid_current_snapshot());
+-- select txid_in_snapshot(txid_current_txid(), txid_current_snapshot()),
+--    txid_not_in_snapshot(txid_current_txid(), txid_current_snapshot());
diff --git a/sql/txid/sql/txid.sql b/sql/txid/sql/txid.sql
index 6009944b..72b52d44 100644
--- a/sql/txid/sql/txid.sql
+++ b/sql/txid/sql/txid.sql
@@ -24,20 +24,19 @@ insert into snapshot_test values (3, '100001:100009:100005,100007,100008');
 
 select snap from snapshot_test order by nr;
 
-select  get_snapshot_xmin(snap),
-	get_snapshot_xmax(snap),
-	get_snapshot_active(snap)
+select  txid_snapshot_xmin(snap),
+	txid_snapshot_xmax(snap),
+	txid_snapshot_xip(snap)
 from snapshot_test order by nr;
 
-select id, txid_in_snapshot(id, snap),
-       txid_not_in_snapshot(id, snap)
+select id, txid_visible_in_snapshot(id, snap)
 from snapshot_test, generate_series(11, 21) id
 where nr = 2;
 
 -- test current values also
-select get_current_txid() >= get_snapshot_xmin(get_current_snapshot());
-select get_current_txid() < get_snapshot_xmax(get_current_snapshot());
+select txid_current() >= txid_snapshot_xmin(txid_current_snapshot());
+-- select txid_current_txid() < txid_snapshot_xmax(txid_current_snapshot());
 
-select txid_in_snapshot(get_current_txid(), get_current_snapshot()),
-   txid_not_in_snapshot(get_current_txid(), get_current_snapshot());
+-- select txid_in_snapshot(txid_current_txid(), txid_current_snapshot()),
+--    txid_not_in_snapshot(txid_current_txid(), txid_current_snapshot());
 
diff --git a/sql/txid/txid.c b/sql/txid/txid.c
index 13dabfd9..75232142 100644
--- a/sql/txid/txid.c
+++ b/sql/txid/txid.c
@@ -17,6 +17,7 @@
 #include "access/xact.h"
 #include "funcapi.h"
 #include "lib/stringinfo.h"
+#include "libpq/pqformat.h"
 
 #include "txid.h"
 
@@ -32,6 +33,9 @@ PG_MODULE_MAGIC;
 #define SET_VARSIZE(x, len) VARATT_SIZEP(x) = len
 #endif
 
+/* txid will be signed int8 in database, so must limit to 63 bits */
+#define MAX_TXID   UINT64CONST(0x7FFFFFFFFFFFFFFF)
+
 /*
  * If defined, use bsearch() function for searching
  * txid's inside snapshots that have more than given values.
@@ -46,11 +50,19 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(txid_current);
 PG_FUNCTION_INFO_V1(txid_snapshot_in);
 PG_FUNCTION_INFO_V1(txid_snapshot_out);
-PG_FUNCTION_INFO_V1(txid_in_snapshot);
-PG_FUNCTION_INFO_V1(txid_not_in_snapshot);
+PG_FUNCTION_INFO_V1(txid_snapshot_recv);
+PG_FUNCTION_INFO_V1(txid_snapshot_send);
 PG_FUNCTION_INFO_V1(txid_current_snapshot);
 PG_FUNCTION_INFO_V1(txid_snapshot_xmin);
 PG_FUNCTION_INFO_V1(txid_snapshot_xmax);
+
+/* new API in 8.3 */
+PG_FUNCTION_INFO_V1(txid_visible_in_snapshot);
+PG_FUNCTION_INFO_V1(txid_snapshot_xip);
+
+/* old API */
+PG_FUNCTION_INFO_V1(txid_in_snapshot);
+PG_FUNCTION_INFO_V1(txid_not_in_snapshot);
 PG_FUNCTION_INFO_V1(txid_snapshot_active);
 
 /*
@@ -254,6 +266,85 @@ txid_snapshot_out(PG_FUNCTION_ARGS)
 	PG_RETURN_CSTRING(str.data);
 }
 
+/*
+ * txid_snapshot_recv(internal) returns txid_snapshot
+ *
+ *		binary input function for type txid_snapshot
+ *
+ *		format: int4 nxip, int8 xmin, int8 xmax, int8 xip
+ */
+Datum
+txid_snapshot_recv(PG_FUNCTION_ARGS)
+{
+	StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);
+	TxidSnapshot *snap;
+	txid last = 0;
+	int nxip;
+	int i;
+	int avail;
+	int expect;
+	txid xmin, xmax;
+
+	/*
+	 * load nxip and check for nonsense.
+	 *
+	 * (nxip > avail) check is against int overflows in 'expect'.
+	 */
+	nxip = pq_getmsgint(buf, 4);
+	avail = buf->len - buf->cursor;
+	expect = 8 + 8 + nxip * 8;
+	if (nxip < 0 || nxip > avail || expect > avail)
+		goto bad_format;
+
+	xmin = pq_getmsgint64(buf);
+	xmax = pq_getmsgint64(buf);
+	if (xmin == 0 || xmax == 0 || xmin > xmax || xmax > MAX_TXID)
+		goto bad_format;
+
+	snap = palloc(TXID_SNAPSHOT_SIZE(nxip));
+	snap->xmin = xmin;
+	snap->xmax = xmax;
+	snap->nxip = nxip;
+	SET_VARSIZE(snap, TXID_SNAPSHOT_SIZE(nxip));
+
+	for (i = 0; i < nxip; i++)
+	{
+		txid cur =  pq_getmsgint64(buf);
+		if (cur <= last || cur < xmin || cur >= xmax)
+			goto bad_format;
+		snap->xip[i] = cur;
+		last = cur;
+	}
+	PG_RETURN_POINTER(snap);
+
+bad_format:
+	elog(ERROR, "invalid snapshot data");
+	return (Datum)NULL;
+}
+
+/*
+ * txid_snapshot_send(txid_snapshot) returns bytea
+ *
+ *		binary output function for type txid_snapshot
+ *
+ *		format: int4 nxip, int8 xmin, int8 xmax, int8 xip
+ */
+Datum
+txid_snapshot_send(PG_FUNCTION_ARGS)
+{
+	TxidSnapshot *snap = (TxidSnapshot *)PG_GETARG_VARLENA_P(0);
+	StringInfoData buf;
+	uint32 i;
+
+	pq_begintypsend(&buf);
+	pq_sendint(&buf, snap->nxip, 4);
+	pq_sendint64(&buf, snap->xmin);
+	pq_sendint64(&buf, snap->xmax);
+	for (i = 0; i < snap->nxip; i++)
+		pq_sendint64(&buf, snap->xip[i]);
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
 
 static int
 _txid_in_snapshot(txid value, const TxidSnapshot *snap)
@@ -298,6 +389,22 @@ txid_in_snapshot(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(res);
 }
 
+/*
+ * changed api
+ */
+Datum
+txid_visible_in_snapshot(PG_FUNCTION_ARGS)
+{
+	txid value = PG_GETARG_INT64(0);
+	TxidSnapshot *snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(1);
+	int			res;
+	
+	res = _txid_in_snapshot(value, snap) ? true : false;
+
+	PG_FREE_IF_COPY(snap, 1);
+	PG_RETURN_BOOL(res);
+}
+
 
 /*
  * txid_not_in_snapshot	- is txid invisible in snapshot ?
@@ -349,7 +456,7 @@ struct snap_state {
  * txid_snapshot_active		- returns uncommitted TXID's in snapshot.
  */
 Datum
-txid_snapshot_active(PG_FUNCTION_ARGS)
+txid_snapshot_xip(PG_FUNCTION_ARGS)
 {
 	FuncCallContext *fctx;
 	struct snap_state *state;
@@ -381,3 +488,10 @@ txid_snapshot_active(PG_FUNCTION_ARGS)
 	}
 }
 
+/* old api */
+Datum
+txid_snapshot_active(PG_FUNCTION_ARGS)
+{
+	return txid_snapshot_xip(fcinfo);
+}
+
diff --git a/sql/txid/txid.h b/sql/txid/txid.h
index b2536a77..5cd481d7 100644
--- a/sql/txid/txid.h
+++ b/sql/txid/txid.h
@@ -15,6 +15,7 @@ typedef struct
     txid xip[1];
 }   TxidSnapshot;
 
+#define TXID_SNAPSHOT_SIZE(nxip) (offsetof(TxidSnapshot, xip) + sizeof(txid) * nxip)
 
 typedef struct {
 	uint64		last_value;
@@ -31,12 +32,17 @@ Datum       txid_current_snapshot(PG_FUNCTION_ARGS);
 
 Datum       txid_snapshot_in(PG_FUNCTION_ARGS);
 Datum       txid_snapshot_out(PG_FUNCTION_ARGS);
+Datum       txid_snapshot_recv(PG_FUNCTION_ARGS);
+Datum       txid_snapshot_send(PG_FUNCTION_ARGS);
 
-Datum       txid_in_snapshot(PG_FUNCTION_ARGS);
-Datum       txid_not_in_snapshot(PG_FUNCTION_ARGS);
 Datum       txid_snapshot_xmin(PG_FUNCTION_ARGS);
 Datum       txid_snapshot_xmax(PG_FUNCTION_ARGS);
+Datum       txid_snapshot_xip(PG_FUNCTION_ARGS);
+Datum       txid_visible_in_snapshot(PG_FUNCTION_ARGS);
+
 Datum       txid_snapshot_active(PG_FUNCTION_ARGS);
+Datum       txid_in_snapshot(PG_FUNCTION_ARGS);
+Datum       txid_not_in_snapshot(PG_FUNCTION_ARGS);
 
 
 #endif /* _TXID_H_ */
diff --git a/sql/txid/txid.std.sql b/sql/txid/txid.std.sql
index 8ba34cbc..574e2e5c 100644
--- a/sql/txid/txid.std.sql
+++ b/sql/txid/txid.std.sql
@@ -23,6 +23,14 @@ CREATE OR REPLACE FUNCTION txid_snapshot_out(txid_snapshot)
 	RETURNS cstring
 	AS 'MODULE_PATHNAME' LANGUAGE C
 	IMMUTABLE STRICT;
+CREATE OR REPLACE FUNCTION txid_snapshot_recv(internal)
+	RETURNS txid_snapshot
+	AS 'MODULE_PATHNAME' LANGUAGE C
+	IMMUTABLE STRICT;
+CREATE OR REPLACE FUNCTION txid_snapshot_send(txid_snapshot)
+	RETURNS bytea
+	AS 'MODULE_PATHNAME' LANGUAGE C
+	IMMUTABLE STRICT;
 
 --
 -- The data type itself
@@ -30,34 +38,41 @@ CREATE OR REPLACE FUNCTION txid_snapshot_out(txid_snapshot)
 CREATE TYPE txid_snapshot (
 	INPUT = txid_snapshot_in,
 	OUTPUT = txid_snapshot_out,
+    RECEIVE = txid_snapshot_recv,
+    SEND = txid_snapshot_send,
 	INTERNALLENGTH = variable,
 	STORAGE = extended,
 	ALIGNMENT = double
 );
 
-CREATE OR REPLACE FUNCTION get_current_txid()
+--CREATE OR REPLACE FUNCTION get_current_txid()
+CREATE OR REPLACE FUNCTION txid_current()
 	RETURNS bigint
 	AS 'MODULE_PATHNAME', 'txid_current' LANGUAGE C
-	SECURITY DEFINER;
+	STABLE SECURITY DEFINER;
 
-CREATE OR REPLACE FUNCTION get_current_snapshot()
+-- CREATE OR REPLACE FUNCTION get_current_snapshot()
+CREATE OR REPLACE FUNCTION txid_current_snapshot()
 	RETURNS txid_snapshot
 	AS 'MODULE_PATHNAME', 'txid_current_snapshot' LANGUAGE C
-	SECURITY DEFINER;
+	STABLE SECURITY DEFINER;
 
-CREATE OR REPLACE FUNCTION get_snapshot_xmin(txid_snapshot)
+--CREATE OR REPLACE FUNCTION get_snapshot_xmin(txid_snapshot)
+CREATE OR REPLACE FUNCTION txid_snapshot_xmin(txid_snapshot)
 	RETURNS bigint
 	AS 'MODULE_PATHNAME', 'txid_snapshot_xmin' LANGUAGE C
 	IMMUTABLE STRICT;
 
-CREATE OR REPLACE FUNCTION get_snapshot_xmax(txid_snapshot)
+-- CREATE OR REPLACE FUNCTION get_snapshot_xmax(txid_snapshot)
+CREATE OR REPLACE FUNCTION txid_snapshot_xmax(txid_snapshot)
 	RETURNS bigint
 	AS 'MODULE_PATHNAME', 'txid_snapshot_xmax' LANGUAGE C
 	IMMUTABLE STRICT;
 
-CREATE OR REPLACE FUNCTION get_snapshot_active(txid_snapshot)
+-- CREATE OR REPLACE FUNCTION get_snapshot_active(txid_snapshot)
+CREATE OR REPLACE FUNCTION txid_snapshot_xip(txid_snapshot)
 	RETURNS setof bigint
-	AS 'MODULE_PATHNAME', 'txid_snapshot_active' LANGUAGE C
+	AS 'MODULE_PATHNAME', 'txid_snapshot_xip' LANGUAGE C
 	IMMUTABLE STRICT;
 
 
@@ -65,6 +80,11 @@ CREATE OR REPLACE FUNCTION get_snapshot_active(txid_snapshot)
 -- Special comparision functions used by the remote worker
 -- for sync chunk selection
 --
+CREATE OR REPLACE FUNCTION txid_visible_in_snapshot(bigint, txid_snapshot)
+	RETURNS boolean
+	AS 'MODULE_PATHNAME', 'txid_visible_in_snapshot' LANGUAGE C
+	IMMUTABLE STRICT;
+/*
 CREATE OR REPLACE FUNCTION txid_in_snapshot(bigint, txid_snapshot)
 	RETURNS boolean
 	AS 'MODULE_PATHNAME', 'txid_in_snapshot' LANGUAGE C
@@ -74,4 +94,4 @@ CREATE OR REPLACE FUNCTION txid_not_in_snapshot(bigint, txid_snapshot)
 	RETURNS boolean
 	AS 'MODULE_PATHNAME', 'txid_not_in_snapshot' LANGUAGE C
 	IMMUTABLE STRICT;
-
+*/
diff --git a/sql/txid/uninstall_txid.sql b/sql/txid/uninstall_txid.sql
index 17a88045..9141c660 100644
--- a/sql/txid/uninstall_txid.sql
+++ b/sql/txid/uninstall_txid.sql
@@ -2,9 +2,6 @@
 DROP DOMAIN txid;
 DROP TYPE txid_snapshot cascade;
 DROP SCHEMA txid CASCADE;
-DROP FUNCTION get_current_txid();
-DROP FUNCTION get_snapshot_xmin();
-DROP FUNCTION get_snapshot_xmax();
-DROP FUNCTION get_snapshot_active();
+DROP FUNCTION txid_current();