Hello
On 07.03.2017 15:58, Masahiko Sawada wrote:
I've read the discussion so far but I didn't see the reason why you've
changed it to as a contrib module. Could you tell me about that?
I did it on the initiative of our customer, who preferred the
implementation in the form of contrib. Contrib realization of WAITLSN
adds to core the only hook.
On 07.03.2017 15:58, Masahiko Sawada wrote:
> I guess this feature would be more useful if provided as a core
> feature and we need to discuss about syntax as Thomas mentioned.
Here I attached rebased patch waitlsn_10dev_v3 (core feature)
I will leave the choice of implementation (core/contrib) to the
discretion of the community.
Will be glad to hear your suggestion about syntax, code and patch.
--
Ivan Kartyshov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2bc4d9f..6d5a81e 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -178,6 +178,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY update SYSTEM "update.sgml">
<!ENTITY vacuum SYSTEM "vacuum.sgml">
<!ENTITY values SYSTEM "values.sgml">
+<!ENTITY waitlsn SYSTEM "waitlsn.sgml">
<!-- applications and utilities -->
<!ENTITY clusterdb SYSTEM "clusterdb.sgml">
diff --git a/doc/src/sgml/ref/waitlsn.sgml b/doc/src/sgml/ref/waitlsn.sgml
new file mode 100644
index 0000000..338187b
--- /dev/null
+++ b/doc/src/sgml/ref/waitlsn.sgml
@@ -0,0 +1,134 @@
+<!--
+doc/src/sgml/ref/waitlsn.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="SQL-WAITLSN">
+ <indexterm zone="sql-waitlsn">
+ <primary>WAITLSN</primary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>WAITLSN</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>WAITLSN</refname>
+ <refpurpose>wait until target <acronym>LSN</> has been replayed</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+WAITLSN <replaceable class="PARAMETER">'LSN'</replaceable> [ , <replaceable class="PARAMETER">delay</replaceable> ]
+WAITLSN_INFINITE <replaceable class="PARAMETER">'LSN'</replaceable>
+WAITLSN_NO_WAIT <replaceable class="PARAMETER">'LSN'</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>WAITLSN</command> wait till target <acronym>LSN</> will
+ be replayed with an optional <quote>delay</> (milliseconds by default
+ infinity) to be wait for LSN to replayed.
+ </para>
+
+ <para>
+ <command>WAITLSN</command> provides a simple
+ interprocess <acronym>LSN</> wait mechanism for a backends on slave
+ in master-slave replication scheme on <productname>PostgreSQL</productname> database.
+ </para>
+
+ <para>
+ The <command>WAITLSN_INFINITE</command> wait till target <acronym>LSN</> will
+ be replayed on slave .
+ </para>
+
+ <para>
+ The <command>WAITLSN_NO_WAIT</command> will tell if target <acronym>LSN</> was replayed without any wait.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="PARAMETER">LSN</replaceable></term>
+ <listitem>
+ <para>
+ Target log sequence number to be wait for.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable class="PARAMETER">delay</replaceable></term>
+ <listitem>
+ <para>
+ Time in miliseconds to waiting for LSN to be replayed.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Delay time for waiting till LSN to be replayed must be integer. For
+ default it is infinity. Waiting can be interupped using Ctl+C, or
+ by Postmaster death.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>GUCs</title>
+
+ <para>
+ Add two GUCs which help tuning influence on StartupXLOG:
+ count_waitlsn (denominator to check not each LSN)
+ int count_waitlsn = 10;
+ </para>
+
+ <para>
+ interval_waitlsn (Interval in milliseconds to additional LSN check)
+ int interval_waitlsn = 100;
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Configure and execute a waitlsn from
+ <application>psql</application>:
+
+<programlisting>
+WAITLSN '0/3F07A6B1', 10000;
+NOTICE: LSN is not reached. Try to make bigger delay.
+WAITLSN
+
+WAITLSN '0/3F07A611';
+WAITLSN
+
+WAITLSN '0/3F0FF791', 500000;
+^CCancel request sent
+NOTICE: LSN is not reached. Try to make bigger delay.
+ERROR: canceling statement due to user request
+</programlisting>
+</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ There is no <command>WAITLSN</command> statement in the SQL
+ standard.
+ </para>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index c8191de..a5100a2 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -206,6 +206,7 @@
&update;
&vacuum;
&values;
+ &waitlsn;
</reference>
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 2dcff7f..9c2def1 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -39,6 +39,7 @@
#include "catalog/pg_control.h"
#include "catalog/pg_database.h"
#include "commands/tablespace.h"
+#include "commands/waitlsn.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "port/atomics.h"
@@ -145,6 +146,9 @@ const struct config_enum_entry sync_method_options[] = {
{NULL, 0, false}
};
+/* GUC variable */
+int count_waitlsn = 10;
+int interval_waitlsn = 100;
/*
* Although only "on", "off", and "always" are documented,
@@ -6948,6 +6952,8 @@ StartupXLOG(void)
{
ErrorContextCallback errcallback;
TimestampTz xtime;
+ TimestampTz time_waitlsn = GetCurrentTimestamp();
+ int counter_waitlsn = 0;
InRedo = true;
@@ -7174,6 +7180,17 @@ StartupXLOG(void)
break;
}
+ /*
+ * After update lastReplayedEndRecPtr set Latches in SHMEM array
+ */
+ if (counter_waitlsn % count_waitlsn == 0
+ || TimestampDifferenceExceeds(time_waitlsn,GetCurrentTimestamp(),interval_waitlsn))
+ {
+ WaitLSNSetLatch();
+ time_waitlsn = GetCurrentTimestamp();
+ }
+ counter_waitlsn++;
+
/* Else, try to fetch the next WAL record */
record = ReadRecord(xlogreader, InvalidXLogRecPtr, LOG, false);
} while (record != NULL);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index e0fab38..8a7e2bd 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -20,6 +20,6 @@ OBJS = amcmds.o aggregatecmds.o alter.o analyze.o async.o cluster.o comment.o \
policy.o portalcmds.o prepare.o proclang.o publicationcmds.o \
schemacmds.o seclabel.o sequence.o subscriptioncmds.o tablecmds.o \
tablespace.o trigger.o tsearchcmds.o typecmds.o user.o vacuum.o \
- vacuumlazy.o variable.o view.o
+ vacuumlazy.o variable.o view.o waitlsn.o
include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c
index e32d7a1..ce1c7f7 100644
--- a/src/backend/commands/async.c
+++ b/src/backend/commands/async.c
@@ -139,7 +139,6 @@
#include "utils/ps_status.h"
#include "utils/timestamp.h"
-
/*
* Maximum size of a NOTIFY payload, including terminating NULL. This
* must be kept small enough so that a notification message fits on one
diff --git a/src/backend/commands/waitlsn.c b/src/backend/commands/waitlsn.c
new file mode 100644
index 0000000..47bd90d
--- /dev/null
+++ b/src/backend/commands/waitlsn.c
@@ -0,0 +1,241 @@
+/*-------------------------------------------------------------------------
+ *
+ * waitlsn.c
+ * WaitLSN statment: WAITLSN
+ *
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2017, Regents of PostgresPro
+ *
+ * IDENTIFICATION
+ * src/backend/commands/waitlsn.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * -------------------------------------------------------------------------
+ * Wait for LSN been replayed on slave
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "fmgr.h"
+#include "pgstat.h"
+#include "utils/pg_lsn.h"
+#include "storage/latch.h"
+#include "miscadmin.h"
+#include "storage/spin.h"
+#include "storage/backendid.h"
+#include "access/xact.h"
+#include "storage/shmem.h"
+#include "storage/ipc.h"
+#include "utils/timestamp.h"
+#include "storage/pmsignal.h"
+#include "access/xlog.h"
+#include "access/xlogdefs.h"
+#include "commands/waitlsn.h"
+#include "storage/proc.h"
+#include "access/transam.h"
+#include "funcapi.h"
+#include "catalog/pg_type.h"
+#include "utils/builtins.h"
+
+/* Latches Own-DisownLatch and AbortCаllBack */
+static uint32 WaitLSNShmemSize(void);
+static void WLDisownLatchAbort(XactEvent event, void *arg);
+static void WLOwnLatch(void);
+static void WLDisownLatch(void);
+
+void _PG_init(void);
+
+/* Shared memory structures */
+typedef struct
+{
+ int pid;
+ volatile slock_t slock;
+ Latch latch;
+} BIDLatch;
+
+typedef struct
+{
+ char dummy;
+ int backend_maxid;
+ BIDLatch l_arr[FLEXIBLE_ARRAY_MEMBER];
+} GlobState;
+
+static volatile GlobState *state;
+bool is_latch_owned = false;
+
+/* Take Latch for current backend at the begining of WAITLSN */
+static void
+WLOwnLatch(void)
+{
+ SpinLockAcquire(&state->l_arr[MyBackendId].slock);
+ OwnLatch(&state->l_arr[MyBackendId].latch);
+ is_latch_owned = true;
+
+ if (state->backend_maxid < MyBackendId)
+ state->backend_maxid = MyBackendId;
+
+ state->l_arr[MyBackendId].pid = MyProcPid;
+ SpinLockRelease(&state->l_arr[MyBackendId].slock);
+}
+
+/* Release Latch for current backend at the end of WAITLSN */
+static void
+WLDisownLatch(void)
+{
+ int i;
+ SpinLockAcquire(&state->l_arr[MyBackendId].slock);
+ DisownLatch(&state->l_arr[MyBackendId].latch);
+ is_latch_owned = false;
+ state->l_arr[MyBackendId].pid = 0;
+
+ if (state->backend_maxid == MyBackendId)
+ for (i = (MaxConnections+1); i >=0; i--)
+ if (state->l_arr[i].pid != 0)
+ {
+ state->backend_maxid = i;
+ break;
+ }
+
+ SpinLockRelease(&state->l_arr[MyBackendId].slock);
+}
+
+/* CallBack function on abort*/
+static void
+WLDisownLatchAbort(XactEvent event, void *arg)
+{
+ if (is_latch_owned && (event == XACT_EVENT_PARALLEL_ABORT ||
+ event == XACT_EVENT_ABORT))
+ {
+ WLDisownLatch();
+ }
+}
+
+/* Module load callback */
+void
+_PG_init(void)
+{
+ if (!IsUnderPostmaster)
+ RegisterXactCallback(WLDisownLatchAbort, NULL);
+}
+
+/* Get size of shared memory to room GlobState */
+static uint32
+WaitLSNShmemSize(void)
+{
+ return offsetof(GlobState, l_arr) + sizeof(BIDLatch) * (MaxConnections+1);
+}
+
+/* Init array of Latches in shared memory */
+void
+WaitLSNShmemInit(void)
+{
+ bool found;
+ uint i;
+
+ state = (GlobState *) ShmemInitStruct("pg_wait_lsn",
+ WaitLSNShmemSize(),
+ &found);
+ if (!found)
+ {
+ for (i = 0; i < (MaxConnections+1); i++)
+ {
+ state->l_arr[i].pid = 0;
+ SpinLockInit(&state->l_arr[i].slock);
+ InitSharedLatch(&state->l_arr[i].latch);
+ }
+ state->backend_maxid = 0;
+ }
+}
+
+/* Set all Latches in shared memorys cause new LSN been replayed*/
+void
+WaitLSNSetLatch(void)
+{
+ uint i;
+ for (i = 0; i <= state->backend_maxid; i++)
+ {
+ SpinLockAcquire(&state->l_arr[i].slock);
+ if (state->l_arr[i].pid != 0)
+ SetLatch(&state->l_arr[i].latch);
+ SpinLockRelease(&state->l_arr[i].slock);
+ }
+}
+
+/*
+ * On WAITLSN own latch and wait till LSN is replayed, Postmaster death, interruption
+ * or timeout.
+ */
+void
+WaitLSNUtility(const char *lsn, const int delay, DestReceiver *dest)
+{
+ XLogRecPtr trg_lsn = DatumGetLSN(DirectFunctionCall1(pg_lsn_in, CStringGetDatum(lsn)));
+ XLogRecPtr cur_lsn;
+ int latch_events;
+ uint64_t tdelay = delay;
+ long secs;
+ int microsecs;
+ TimestampTz timer = GetCurrentTimestamp();
+ TupOutputState *tstate;
+ TupleDesc tupdesc;
+ char *value = "false";
+
+ if (delay > 0)
+ latch_events = WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH;
+ else
+ latch_events = WL_LATCH_SET | WL_POSTMASTER_DEATH;
+
+ WLOwnLatch();
+
+ for (;;)
+ {
+ cur_lsn = GetXLogReplayRecPtr(NULL);
+
+ /* If LSN had been Replayed */
+ if (trg_lsn <= cur_lsn)
+ break;
+
+ /* If the postmaster dies, finish immediately */
+ if (!PostmasterIsAlive())
+ break;
+
+ /* If Delay time is over */
+ if (latch_events & WL_TIMEOUT)
+ {
+ if (TimestampDifferenceExceeds(timer,GetCurrentTimestamp(),delay))
+ break;
+ TimestampDifference(timer,GetCurrentTimestamp(),&secs, µsecs);
+ tdelay = delay - (secs*1000 + microsecs/1000);
+ }
+
+ MyPgXact->xmin = InvalidTransactionId;
+ WaitLatch(&state->l_arr[MyBackendId].latch, latch_events, tdelay, WAIT_EVENT_CLIENT_READ);
+ ResetLatch(&state->l_arr[MyBackendId].latch);
+
+ /* CHECK_FOR_INTERRUPTS if they comes then disown latch current */
+ if (InterruptPending)
+ {
+ WLDisownLatch();
+ ProcessInterrupts();
+ }
+
+ }
+
+ WLDisownLatch();
+
+ if (trg_lsn > cur_lsn)
+ elog(NOTICE,"LSN is not reached. Try to make bigger delay.");
+ else
+ value = "true";
+
+ /* need a tuple descriptor representing a single TEXT column */
+ tupdesc = CreateTemplateTupleDesc(1, false);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 1, "LSN reached", TEXTOID, -1, 0);
+ /* prepare for projection of tuples */
+ tstate = begin_tup_output_tupdesc(dest, tupdesc);
+ /* Send it */
+ do_text_output_oneline(tstate, value);
+ end_tup_output(tstate);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 174773b..dcaed39 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -275,7 +275,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
SecLabelStmt SelectStmt TransactionStmt TruncateStmt
UnlistenStmt UpdateStmt VacuumStmt
VariableResetStmt VariableSetStmt VariableShowStmt
- ViewStmt CheckPointStmt CreateConversionStmt
+ ViewStmt WaitLSNStmt CheckPointStmt CreateConversionStmt
DeallocateStmt PrepareStmt ExecuteStmt
DropOwnedStmt ReassignOwnedStmt
AlterTSConfigurationStmt AlterTSDictionaryStmt
@@ -320,7 +320,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <list> OptSchemaEltList
%type <boolean> TriggerForSpec TriggerForType
-%type <ival> TriggerActionTime
+%type <ival> TriggerActionTime WaitDelay
%type <list> TriggerEvents TriggerOneEvent
%type <value> TriggerFuncArg
%type <node> TriggerWhen
@@ -678,7 +678,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
VERBOSE VERSION_P VIEW VIEWS VOLATILE
- WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
+ WAITLSN WAITLSN_INFINITE WAITLSN_NO_WAIT WHEN WHERE WHITESPACE_P WINDOW
+ WITH WITHIN WITHOUT WORK WRAPPER WRITE
XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLPARSE
XMLPI XMLROOT XMLSERIALIZE
@@ -935,6 +936,7 @@ stmt :
| VariableSetStmt
| VariableShowStmt
| ViewStmt
+ | WaitLSNStmt
| /*EMPTY*/
{ $$ = NULL; }
;
@@ -13507,7 +13509,41 @@ frame_bound:
}
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * WAITLSN <LSN> can appear as a query-level command
+ *
+ *
+ *****************************************************************************/
+WaitLSNStmt:
+ WAITLSN Sconst WaitDelay
+ {
+ WaitLSNStmt *n = makeNode(WaitLSNStmt);
+ n->lsn = $2;
+ n->delay = $3;
+ $$ = (Node *)n;
+ }
+ | WAITLSN_INFINITE Sconst
+ {
+ WaitLSNStmt *n = makeNode(WaitLSNStmt);
+ n->lsn = $2;
+ n->delay = 0;
+ $$ = (Node *)n;
+ }
+ | WAITLSN_NO_WAIT Sconst
+ {
+ WaitLSNStmt *n = makeNode(WaitLSNStmt);
+ n->lsn = $2;
+ n->delay = 1;
+ $$ = (Node *)n;
+ }
+ ;
+WaitDelay:
+ ',' Iconst { $$ = $2; }
+ | /*EMPTY*/ { $$ = 0; }
+ ;
/*
* Supporting nonterminals for expressions.
*/
@@ -14541,6 +14577,9 @@ unreserved_keyword:
| VIEW
| VIEWS
| VOLATILE
+ | WAITLSN
+ | WAITLSN_INFINITE
+ | WAITLSN_NO_WAIT
| WHITESPACE_P
| WITHIN
| WITHOUT
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 2d1ed14..932136f 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -22,6 +22,7 @@
#include "access/subtrans.h"
#include "access/twophase.h"
#include "commands/async.h"
+#include "commands/waitlsn.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
@@ -271,6 +272,11 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int port)
AsyncShmemInit();
BackendRandomShmemInit();
+ /*
+ * Init array of Latches in SHMEM for WAITLSN
+ */
+ WaitLSNShmemInit();
+
#ifdef EXEC_BACKEND
/*
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 5d3be38..6595be6 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -56,6 +56,7 @@
#include "commands/user.h"
#include "commands/vacuum.h"
#include "commands/view.h"
+#include "commands/waitlsn.h"
#include "miscadmin.h"
#include "parser/parse_utilcmd.h"
#include "postmaster/bgwriter.h"
@@ -917,6 +918,20 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_WaitLSNStmt:
+ {
+ WaitLSNStmt *stmt = (WaitLSNStmt *) parsetree;
+ if (!RecoveryInProgress())
+ {
+ ereport(ERROR,(errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
+ errmsg("cannot execute %s not during recovery",
+ "WaitLSN")));
+ }
+ else
+ WaitLSNUtility(stmt->lsn, stmt->delay, dest);
+ }
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2453,6 +2468,10 @@ CreateCommandTag(Node *parsetree)
tag = "NOTIFY";
break;
+ case T_WaitLSNStmt:
+ tag = "WAITLSN";
+ break;
+
case T_ListenStmt:
tag = "LISTEN";
break;
@@ -3064,6 +3083,10 @@ GetCommandLogLevel(Node *parsetree)
lev = LOGSTMT_ALL;
break;
+ case T_WaitLSNStmt:
+ lev = LOGSTMT_ALL;
+ break;
+
case T_ListenStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 0249721..ab52ed4 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2835,6 +2835,30 @@ static struct config_int ConfigureNamesInt[] =
NULL, NULL, NULL
},
+ {
+ {"interval_waitlsn", PGC_SUSET, DEVELOPER_OPTIONS,
+ gettext_noop("Set interval of time (ms) how often LSN will be checked."),
+ gettext_noop("Set interval of time (ms) how often LSN will be checked to "
+ "make less influence on StartupXLOG() process."),
+ GUC_UNIT_MS
+ },
+ &interval_waitlsn,
+ 100, 0, INT_MAX,
+ NULL, NULL, NULL
+ },
+
+ {
+ {"count_waitlsn", PGC_SUSET, DEVELOPER_OPTIONS,
+ gettext_noop("How often LSN will be checked."),
+ gettext_noop("Set count of LSNs that will be passed befor LSN check to "
+ "make less influence on StartupXLOG() process."),
+ GUC_NOT_IN_SAMPLE
+ },
+ &count_waitlsn,
+ 10, 1, INT_MAX,
+ NULL, NULL, NULL
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 9f036c7..5249c8e 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -111,6 +111,9 @@ extern bool log_checkpoints;
extern int CheckPointSegments;
+extern int interval_waitlsn;
+extern int count_waitlsn;
+
/* Archive modes */
typedef enum ArchiveMode
{
diff --git a/src/include/commands/waitlsn.h b/src/include/commands/waitlsn.h
new file mode 100644
index 0000000..2e39608
--- /dev/null
+++ b/src/include/commands/waitlsn.h
@@ -0,0 +1,21 @@
+/*-------------------------------------------------------------------------
+ *
+ * waitlsn.h
+ * WaitLSN notification: WAITLSN
+ *
+ * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2016, Regents of PostgresPRO
+ *
+ * src/include/commands/waitlsn.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef WAITLSN_H
+#define WAITLSN_H
+#include "tcop/dest.h"
+
+extern void WaitLSNUtility(const char *lsn, const int delay, DestReceiver *dest);
+extern void WaitLSNShmemInit(void);
+extern void WaitLSNSetLatch(void);
+
+#endif /* WAITLSN_H */
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 95dd8ba..5f02105 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -478,6 +478,7 @@ typedef enum NodeTag
T_DropReplicationSlotCmd,
T_StartReplicationCmd,
T_TimeLineHistoryCmd,
+ T_WaitLSNStmt,
/*
* TAGS FOR RANDOM OTHER STUFF
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 07a8436..732304d 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3299,4 +3299,16 @@ typedef struct DropSubscriptionStmt
bool missing_ok; /* Skip error if missing? */
} DropSubscriptionStmt;
+/* ----------------------
+ * WaitLSN Statement
+ * ----------------------
+ */
+typedef struct WaitLSNStmt
+{
+ NodeTag type;
+ char *lsn; /* Taraget LSN to wait for */
+ int delay; /* Delay to wait for LSN*/
+ bool nowait; /* No wait for LSN just result*/
+} WaitLSNStmt;
+
#endif /* PARSENODES_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 985d650..c77f7b5 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -430,6 +430,9 @@ PG_KEYWORD("version", VERSION_P, UNRESERVED_KEYWORD)
PG_KEYWORD("view", VIEW, UNRESERVED_KEYWORD)
PG_KEYWORD("views", VIEWS, UNRESERVED_KEYWORD)
PG_KEYWORD("volatile", VOLATILE, UNRESERVED_KEYWORD)
+PG_KEYWORD("waitlsn", WAITLSN, UNRESERVED_KEYWORD)
+PG_KEYWORD("waitlsn_infinite", WAITLSN_INFINITE, UNRESERVED_KEYWORD)
+PG_KEYWORD("waitlsn_no_wait", WAITLSN_NO_WAIT, UNRESERVED_KEYWORD)
PG_KEYWORD("when", WHEN, RESERVED_KEYWORD)
PG_KEYWORD("where", WHERE, RESERVED_KEYWORD)
PG_KEYWORD("whitespace", WHITESPACE_P, UNRESERVED_KEYWORD)
--
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