New statistics for WAL buffer dirty writes

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 642c129..893acf8 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -370,6 +370,11 @@ typedef struct XLogCtlWrite
 {
 	int			curridx;		/* cache index of next block to write */
 	pg_time_t	lastSegSwitchTime;		/* time of last xlog segment switch */
+
+	/*
+	 * Counter for WAL dirty buffer writes.
+	 */
+	uint64		WalBufferWriteDirtyCount;
 } XLogCtlWrite;
 
 /*
@@ -1504,6 +1509,8 @@ AdvanceXLInsertBuffer(bool new_segment)
 			}
 			else
 			{
+				XLogCtlWrite *Write = &XLogCtl->Write;
+
 				/*
 				 * Have to write buffers while holding insert lock. This is
 				 * not good, so only write as much as we absolutely must.
@@ -1512,6 +1519,10 @@ AdvanceXLInsertBuffer(bool new_segment)
 				WriteRqst.Write = OldPageRqstPtr;
 				WriteRqst.Flush = 0;
 				XLogWrite(WriteRqst, false, false);
+				/*
+				 * XLogCtrlWrite must be protected with WALWriteLock.
+				 */
+				Write->WalBufferWriteDirtyCount++;
 				LWLockRelease(WALWriteLock);
 				TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 			}
@@ -10492,3 +10503,26 @@ SetWalWriterSleeping(bool sleeping)
 	xlogctl->WalWriterSleeping = sleeping;
 	SpinLockRelease(&xlogctl->info_lck);
 }
+
+uint64
+xlog_dirty_write_counter_get()
+{
+	XLogCtlWrite *Write = &XLogCtl->Write;
+	uint64 count;
+
+	LWLockAcquire(WALWriteLock, LW_SHARED);
+	count =	Write->WalBufferWriteDirtyCount;
+	LWLockRelease(WALWriteLock);
+
+	return count;
+}
+
+void
+xlog_dirty_write_counter_reset()
+{
+	XLogCtlWrite *Write = &XLogCtl->Write;
+
+	LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
+	Write->WalBufferWriteDirtyCount = 0;
+	LWLockRelease(WALWriteLock);
+}
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 7c0705a..d544a5b 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -117,6 +117,9 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_write(PG_FUNCTION_ARGS);
+extern Datum pg_stat_reset_xlog_dirty_write(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1700,3 +1703,16 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_write(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(xlog_dirty_write_counter_get());
+}
+
+Datum
+pg_stat_reset_xlog_dirty_write(PG_FUNCTION_ARGS)
+{
+	xlog_dirty_write_counter_reset();
+	PG_RETURN_VOID();
+}
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index ec79870..01343b9 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -325,6 +325,9 @@ extern XLogRecPtr do_pg_start_backup(const char *backupidstr, bool fast, char **
 extern XLogRecPtr do_pg_stop_backup(char *labelfile, bool waitforarchive);
 extern void do_pg_abort_backup(void);
 
+extern uint64 xlog_dirty_write_counter_get(void);
+extern void xlog_dirty_write_counter_reset(void);
+
 /* File path names (all relative to $PGDATA) */
 #define BACKUP_LABEL_FILE		"backup_label"
 #define BACKUP_LABEL_OLD		"backup_label.old"
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index bee7154..e21f57e 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2736,6 +2736,11 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3766 (  pg_stat_get_xlog_dirty_write  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_write _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+DATA(insert OID = 3767 (  pg_stat_reset_xlog_dirty_write  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 2278 "" _null_ _null_ _null_ _null_ pg_stat_reset_xlog_dirty_write _null_ _null_ _null_ ));
+DESCR("statistics: reset xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index ff56c26..234d568 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1518,6 +1518,7 @@ AdvanceXLInsertBuffer(bool new_segment)
 				WriteRqst.Write = OldPageRqstPtr;
 				WriteRqst.Flush = 0;
 				XLogWrite(WriteRqst, false, false);
+				WalWriterStats.m_xlog_dirty_writes++;
 				LWLockRelease(WALWriteLock);
 				TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 			}
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 8389d5c..f031be1 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -125,6 +125,15 @@ char	   *pgstat_stat_tmpname = NULL;
  */
 PgStat_MsgBgWriter BgWriterStats;
 
+/*
+ * WalWriter global statistics counter.
+ * Despite its name, this counter is actually used not only in walwriter,
+ * but also in each backend process to sum up xlog dirty writes.
+ * Those processes would increment this counter in each XLogWrite call,
+ * then send it to the stat collector process.
+ */
+PgStat_MsgWalWriter WalWriterStats;
+
 /* ----------
  * Local data
  * ----------
@@ -279,6 +288,7 @@ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
 static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
 static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
 static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
+static void pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
@@ -1188,6 +1198,8 @@ pgstat_reset_shared_counters(const char *target)
 
 	if (strcmp(target, "bgwriter") == 0)
 		msg.m_resettarget = RESET_BGWRITER;
+	else if (strcmp(target, "walwriter") == 0)
+		msg.m_resettarget = RESET_WALWRITER;
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -2988,6 +3000,38 @@ pgstat_send_bgwriter(void)
 	MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
 }
 
+/* ----------
+ * pgstat_send_walwriter() -
+ *
+ *		Send walwriter statistics to the collector
+ * ----------
+ */
+void
+pgstat_send_walwriter(void)
+{
+	/* We assume this initializes to zeroes */
+	static const PgStat_MsgBgWriter all_zeroes;
+
+	/*
+	 * This function can be called even if nothing at all has happened. In
+	 * this case, avoid sending a completely empty message to the stats
+	 * collector.
+	 */
+	if (memcmp(&WalWriterStats, &all_zeroes, sizeof(PgStat_MsgWalWriter)) == 0)
+		return;
+
+	/*
+	 * Prepare and send the message
+	 */
+	pgstat_setheader(&WalWriterStats.m_hdr, PGSTAT_MTYPE_WALWRITER);
+	pgstat_send(&WalWriterStats, sizeof(WalWriterStats));
+
+	/*
+	 * Clear out the statistics buffer, so it can be re-used.
+	 */
+	MemSet(&WalWriterStats, 0, sizeof(WalWriterStats));
+}
+
 
 /* ----------
  * PgstatCollectorMain() -
@@ -3207,6 +3251,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_WALWRITER:
+					pgstat_recv_walwriter((PgStat_MsgWalWriter *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_FUNCSTAT:
 					pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
 					break;
@@ -4382,6 +4430,12 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len)
 		memset(&globalStats, 0, sizeof(globalStats));
 		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
 	}
+	else if (msg->m_resettarget == RESET_WALWRITER)
+	{
+		/* Reset the global walwriter statistics for the cluster. */
+		memset(&globalStats, 0, sizeof(globalStats));
+		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	}
 
 	/*
 	 * Presumably the sender of this message validated the target, don't
@@ -4534,6 +4588,18 @@ pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
 }
 
 /* ----------
+ * pgstat_recv_walwriter() -
+ *
+ *	Process a WALWRITER message.
+ * ----------
+ */
+static void
+pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len)
+{
+	globalStats.xlog_dirty_writes += msg->m_xlog_dirty_writes;
+}
+
+/* ----------
  * pgstat_recv_recoveryconflict() -
  *
  *	Process a RECOVERYCONFLICT message.
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 4313901..6fbc5f9 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -289,6 +289,8 @@ WalWriterMain(void)
 		else if (left_till_hibernate > 0)
 			left_till_hibernate--;
 
+		pgstat_send_walwriter();
+
 		/*
 		 * Sleep until we are signaled or WalWriterDelay has elapsed.  If we
 		 * haven't done anything useful for quite some time, lengthen the
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index f1248a8..1ed2c0a 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3918,6 +3918,8 @@ PostgresMain(int argc, char *argv[], const char *username)
 				pgstat_report_activity(STATE_IDLE, NULL);
 			}
 
+			pgstat_send_walwriter();
+
 			ReadyForQuery(whereToSendOutput);
 			send_ready_for_query = false;
 		}
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 7d4059f..f707c9a 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -118,6 +118,8 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1701,3 +1703,9 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(pgstat_fetch_global()->xlog_dirty_writes);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 77a3b41..da2225c 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2740,6 +2740,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3766 (  pg_stat_get_xlog_dirty_writes  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_writes _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 613c1c2..59aa1ba 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -45,6 +45,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_VACUUM,
 	PGSTAT_MTYPE_ANALYZE,
 	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WALWRITER,
 	PGSTAT_MTYPE_FUNCSTAT,
 	PGSTAT_MTYPE_FUNCPURGE,
 	PGSTAT_MTYPE_RECOVERYCONFLICT,
@@ -102,7 +103,8 @@ typedef struct PgStat_TableCounts
 /* Possible targets for resetting cluster-wide shared values */
 typedef enum PgStat_Shared_Reset_Target
 {
-	RESET_BGWRITER
+	RESET_BGWRITER,
+	RESET_WALWRITER
 } PgStat_Shared_Reset_Target;
 
 /* Possible object types for resetting single counters */
@@ -372,6 +374,17 @@ typedef struct PgStat_MsgBgWriter
 } PgStat_MsgBgWriter;
 
 /* ----------
+ * PgStat_MsgWalWriter			Sent by the walwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWalWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_xlog_dirty_writes;
+} PgStat_MsgWalWriter;
+
+/* ----------
  * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
  * ----------
  */
@@ -499,6 +512,7 @@ typedef union PgStat_Msg
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
 	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWalWriter msg_walwriter;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
@@ -622,6 +636,7 @@ typedef struct PgStat_GlobalStats
 	PgStat_Counter buf_written_backend;
 	PgStat_Counter buf_fsync_backend;
 	PgStat_Counter buf_alloc;
+	PgStat_Counter xlog_dirty_writes;
 	TimestampTz stat_reset_timestamp;
 } PgStat_GlobalStats;
 
@@ -730,6 +745,8 @@ extern char *pgstat_stat_filename;
  */
 extern PgStat_MsgBgWriter BgWriterStats;
 
+extern PgStat_MsgWalWriter WalWriterStats;
+
 /*
  * Updated by pgstat_count_buffer_*_time macros
  */
@@ -858,6 +875,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 						  void *recdata, uint32 len);
 
 extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_walwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index b4fcbaf..0ae885b 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1907,6 +1907,13 @@ include 'filename'
         results in most cases.
        </para>
 
+       <para>
+        When you see pg_stat_walwriter.dirty_write, which means number
+        of buffer flushing at buffer full, is continuously increasing
+        in your running server, you may need to enlarge this buffer
+        size.
+       </para>
+
       </listitem>
      </varlistentry>
 
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 39ccfbb..3117f91 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -278,6 +278,14 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
      </row>
 
      <row>
+      <entry><structname>pg_stat_walwriter</><indexterm><primary>pg_stat_walwriter</primary></indexterm></entry>
+      <entry>One row only, showing statistics about the wal writer
+       process's activity. See <xref linkend="pg-stat-walwriter-view">
+       for details.
+     </entry>
+     </row>
+
+     <row>
       <entry><structname>pg_stat_database</><indexterm><primary>pg_stat_database</primary></indexterm></entry>
       <entry>One row per database, showing database-wide statistics. See
        <xref linkend="pg-stat-database-view"> for details.
@@ -735,6 +743,39 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    single row, containing global data for the cluster.
   </para>
 
+  <table id="pg-stat-walwriter-view" xreflabel="pg_stat_walwriter">
+   <title><structname>pg_stat_walwriter</structname> View</title>
+
+   <tgroup cols="3">
+    <thead>
+    <row>
+      <entry>Column</entry>
+      <entry>Type</entry>
+      <entry>Description</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry><structfield>dirty_writes</></entry>
+      <entry><type>bigint</type></entry>
+      <entry>Number of dirty writes, which means flushing wal buffers
+       because of its full.</entry>
+     </row>
+     <row>
+      <entry><structfield>stats_reset</></entry>
+      <entry><type>timestamp with time zone</type></entry>
+      <entry>Time at which these statistics were last reset</entry>
+     </row>
+    </tbody>
+    </tgroup>
+  </table>
+
+  <para>
+   The <structname>pg_stat_walwriter</structname> view will always have a
+   single row, containing global data for the cluster.
+  </para>
+
   <table id="pg-stat-database-view" xreflabel="pg_stat_database">
    <title><structname>pg_stat_database</structname> View</title>
    <tgroup cols="3">
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index d251d08..631a0af 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1347,6 +1347,7 @@ AdvanceXLInsertBuffer(bool new_segment)
 				WriteRqst.Write = OldPageRqstPtr;
 				WriteRqst.Flush = 0;
 				XLogWrite(WriteRqst, false, false);
+				WalWriterStats.m_xlog_dirty_writes++;
 				LWLockRelease(WALWriteLock);
 				TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 			}
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 607a72f..40f0c34 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -671,6 +671,11 @@ CREATE VIEW pg_stat_bgwriter AS
         pg_stat_get_buf_alloc() AS buffers_alloc,
         pg_stat_get_bgwriter_stat_reset_time() AS stats_reset;
 
+CREATE VIEW pg_stat_walwriter AS
+    SELECT
+        pg_stat_get_xlog_dirty_writes() AS dirty_writes,
+        pg_stat_get_wal_stat_reset_time() AS stats_reset;
+
 CREATE VIEW pg_user_mappings AS
     SELECT
         U.oid       AS umid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index be3adf1..5be78c6 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -125,6 +125,15 @@ char	   *pgstat_stat_tmpname = NULL;
  */
 PgStat_MsgBgWriter BgWriterStats;
 
+/*
+ * WalWriter global statistics counter.
+ * Despite its name, this counter is actually used not only in walwriter,
+ * but also in each backend process to sum up xlog dirty writes.
+ * Those processes would increment this counter in each XLogWrite call,
+ * then send it to the stat collector process.
+ */
+PgStat_MsgWalWriter WalWriterStats;
+
 /* ----------
  * Local data
  * ----------
@@ -279,6 +288,7 @@ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
 static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
 static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
 static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
+static void pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
@@ -762,6 +772,9 @@ pgstat_report_stat(bool force)
 
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
+
+	/* Now, send wal buffer flush statistics */
+	pgstat_send_walwriter();
 }
 
 /*
@@ -1188,11 +1201,13 @@ pgstat_reset_shared_counters(const char *target)
 
 	if (strcmp(target, "bgwriter") == 0)
 		msg.m_resettarget = RESET_BGWRITER;
+	else if (strcmp(target, "walwriter") == 0)
+		msg.m_resettarget = RESET_WALWRITER;
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized reset target: \"%s\"", target),
-				 errhint("Target must be \"bgwriter\".")));
+				 errhint("Target must be \"bgwriter\" or \"walwriter\".")));
 
 	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER);
 	pgstat_send(&msg, sizeof(msg));
@@ -2988,6 +3003,38 @@ pgstat_send_bgwriter(void)
 	MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
 }
 
+/* ----------
+ * pgstat_send_walwriter() -
+ *
+ *		Send walwriter statistics to the collector
+ * ----------
+ */
+void
+pgstat_send_walwriter(void)
+{
+	/* We assume this initializes to zeroes */
+	static const PgStat_MsgBgWriter all_zeroes;
+
+	/*
+	 * This function can be called even if nothing at all has happened. In
+	 * this case, avoid sending a completely empty message to the stats
+	 * collector.
+	 */
+	if (memcmp(&WalWriterStats, &all_zeroes, sizeof(PgStat_MsgWalWriter)) == 0)
+		return;
+
+	/*
+	 * Prepare and send the message
+	 */
+	pgstat_setheader(&WalWriterStats.m_hdr, PGSTAT_MTYPE_WALWRITER);
+	pgstat_send(&WalWriterStats, sizeof(WalWriterStats));
+
+	/*
+	 * Clear out the statistics buffer, so it can be re-used.
+	 */
+	MemSet(&WalWriterStats, 0, sizeof(WalWriterStats));
+}
+
 
 /* ----------
  * PgstatCollectorMain() -
@@ -3209,6 +3256,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_WALWRITER:
+					pgstat_recv_walwriter((PgStat_MsgWalWriter *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_FUNCSTAT:
 					pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
 					break;
@@ -3638,7 +3689,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
 	 * Set the current timestamp (will be kept only in case we can't load an
 	 * existing statsfile).
 	 */
-	globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.stat_bgw_reset_timestamp = GetCurrentTimestamp();
+	globalStats.stat_wal_reset_timestamp = GetCurrentTimestamp();
 
 	/*
 	 * Try to open the status file. If it doesn't exist, the backends simply
@@ -4381,8 +4433,23 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len)
 	if (msg->m_resettarget == RESET_BGWRITER)
 	{
 		/* Reset the global background writer statistics for the cluster. */
-		memset(&globalStats, 0, sizeof(globalStats));
-		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+		globalStats.timed_checkpoints       = 0;
+		globalStats.requested_checkpoints   = 0;
+		globalStats.checkpoint_write_time   = 0;
+		globalStats.checkpoint_sync_time    = 0;
+		globalStats.buf_written_checkpoints = 0;
+		globalStats.buf_written_clean       = 0;
+		globalStats.maxwritten_clean        = 0;
+		globalStats.buf_written_backend     = 0;
+		globalStats.buf_fsync_backend       = 0;
+		globalStats.buf_alloc               = 0;
+		globalStats.stat_bgw_reset_timestamp = GetCurrentTimestamp();
+	}
+	else if (msg->m_resettarget == RESET_WALWRITER)
+	{
+		/* Reset the global walwriter statistics for the cluster. */
+		globalStats.xlog_dirty_writes = 0;
+		globalStats.stat_wal_reset_timestamp = GetCurrentTimestamp();
 	}
 
 	/*
@@ -4536,6 +4603,18 @@ pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
 }
 
 /* ----------
+ * pgstat_recv_walwriter() -
+ *
+ *	Process a WALWRITER message.
+ * ----------
+ */
+static void
+pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len)
+{
+	globalStats.xlog_dirty_writes += msg->m_xlog_dirty_writes;
+}
+
+/* ----------
  * pgstat_recv_recoveryconflict() -
  *
  *	Process a RECOVERYCONFLICT message.
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index c3e15ef..cd294fb 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -290,6 +290,8 @@ WalWriterMain(void)
 		else if (left_till_hibernate > 0)
 			left_till_hibernate--;
 
+		pgstat_send_walwriter();
+
 		/*
 		 * Sleep until we are signaled or WalWriterDelay has elapsed.  If we
 		 * haven't done anything useful for quite some time, lengthen the
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 7d4059f..fc25dda 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -97,6 +97,7 @@ extern Datum pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_alloc(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS);
 
 extern Datum pg_stat_get_xact_numscans(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_xact_tuples_returned(PG_FUNCTION_ARGS);
@@ -118,6 +119,8 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1443,7 +1446,7 @@ pg_stat_get_checkpoint_sync_time(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_reset_timestamp);
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_bgw_reset_timestamp);
 }
 
 Datum
@@ -1465,6 +1468,12 @@ pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)
 }
 
 Datum
+pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_wal_reset_timestamp);
+}
+
+Datum
 pg_stat_get_xact_numscans(PG_FUNCTION_ARGS)
 {
 	Oid			relid = PG_GETARG_OID(0);
@@ -1701,3 +1710,9 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(pgstat_fetch_global()->xlog_dirty_writes);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index f935eb1..d6edb5a 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2702,6 +2702,8 @@ DATA(insert OID = 3063 ( pg_stat_get_buf_fsync_backend PGNSP PGUID 12 1 0 0 0 f
 DESCR("statistics: number of backend buffer writes that did their own fsync");
 DATA(insert OID = 2859 ( pg_stat_get_buf_alloc			PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_alloc _null_ _null_ _null_ ));
 DESCR("statistics: number of buffer allocations");
+DATA(insert OID = 2860 ( pg_stat_get_wal_stat_reset_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_	pg_stat_get_wal_stat_reset_time _null_ _null_ _null_ ));
+DESCR("statistics: last reset for the wal");
 
 DATA(insert OID = 2978 (  pg_stat_get_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls");
@@ -2746,6 +2748,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3766 (  pg_stat_get_xlog_dirty_writes  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_writes _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 613c1c2..f71c538 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -45,6 +45,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_VACUUM,
 	PGSTAT_MTYPE_ANALYZE,
 	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WALWRITER,
 	PGSTAT_MTYPE_FUNCSTAT,
 	PGSTAT_MTYPE_FUNCPURGE,
 	PGSTAT_MTYPE_RECOVERYCONFLICT,
@@ -102,7 +103,8 @@ typedef struct PgStat_TableCounts
 /* Possible targets for resetting cluster-wide shared values */
 typedef enum PgStat_Shared_Reset_Target
 {
-	RESET_BGWRITER
+	RESET_BGWRITER,
+	RESET_WALWRITER
 } PgStat_Shared_Reset_Target;
 
 /* Possible object types for resetting single counters */
@@ -372,6 +374,17 @@ typedef struct PgStat_MsgBgWriter
 } PgStat_MsgBgWriter;
 
 /* ----------
+ * PgStat_MsgWalWriter			Sent by the walwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWalWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_xlog_dirty_writes;
+} PgStat_MsgWalWriter;
+
+/* ----------
  * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
  * ----------
  */
@@ -499,6 +512,7 @@ typedef union PgStat_Msg
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
 	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWalWriter msg_walwriter;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
@@ -622,7 +636,10 @@ typedef struct PgStat_GlobalStats
 	PgStat_Counter buf_written_backend;
 	PgStat_Counter buf_fsync_backend;
 	PgStat_Counter buf_alloc;
-	TimestampTz stat_reset_timestamp;
+	TimestampTz stat_bgw_reset_timestamp;
+
+	PgStat_Counter xlog_dirty_writes;
+	TimestampTz stat_wal_reset_timestamp;
 } PgStat_GlobalStats;
 
 
@@ -730,6 +747,8 @@ extern char *pgstat_stat_filename;
  */
 extern PgStat_MsgBgWriter BgWriterStats;
 
+extern PgStat_MsgWalWriter WalWriterStats;
+
 /*
  * Updated by pgstat_count_buffer_*_time macros
  */
@@ -858,6 +877,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 						  void *recdata, uint32 len);
 
 extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_walwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to

diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c
index e376452..334ce4c 100644
--- a/contrib/pgbench/pgbench.c
+++ b/contrib/pgbench/pgbench.c
@@ -135,6 +135,11 @@ int			unlogged_tables = 0;
 double		sample_rate = 0.0;
 
 /*
+ * logging steps (seconds between log messages)
+ */
+int			log_step_seconds = 5;
+
+/*
  * tablespace selection
  */
 char	   *tablespace = NULL;
@@ -1362,6 +1367,11 @@ init(bool is_no_vacuum)
 	char		sql[256];
 	int			i;
 
+	/* used to track elapsed time and estimate of the remaining time */
+	instr_time	start, diff;
+	double		elapsed_sec, remaining_sec;
+	int			log_interval = 1;
+
 	if ((con = doConnect()) == NULL)
 		exit(1);
 
@@ -1430,6 +1440,8 @@ init(bool is_no_vacuum)
 	}
 	PQclear(res);
 
+	INSTR_TIME_SET_CURRENT(start);
+
 	for (i = 0; i < naccounts * scale; i++)
 	{
 		int			j = i + 1;
@@ -1441,10 +1453,27 @@ init(bool is_no_vacuum)
 			exit(1);
 		}
 
-		if (j % 100000 == 0)
-			fprintf(stderr, "%d of %d tuples (%d%%) done.\n",
-					j, naccounts * scale,
-					(int) (((int64) j * 100) / (naccounts * scale)));
+		/* let's not call the timing for each row, but only each 100 rows */
+		if (j % 100 == 0 || j == scale * naccounts)
+		{
+			INSTR_TIME_SET_CURRENT(diff);
+			INSTR_TIME_SUBTRACT(diff, start);
+
+			elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
+			remaining_sec = (scale * naccounts - j) * elapsed_sec / j;
+
+			/* have we reached the next interval? */
+			if (elapsed_sec >= log_interval * log_step_seconds) {
+
+				fprintf(stderr, "%d of %d tuples (%d%%) done (elapsed %.2f s, remaining %.2f s).\n",
+						j, naccounts * scale,
+						(int) (((int64) j * 100) / (naccounts * scale)), elapsed_sec, remaining_sec);
+
+				/* skip to the next interval */
+				log_interval = (int)ceil(elapsed_sec/log_step_seconds);
+			}
+		}
+
 	}
 	if (PQputline(con, "\\.\n"))
 	{
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index b7df8ce..bf9acc5 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1919,6 +1919,13 @@ include 'filename'
         results in most cases.
        </para>
 
+       <para>
+        When you see pg_stat_walwriter.dirty_write, which means number
+        of buffer flushing at buffer full, is continuously increasing
+        in your running server, you may need to enlarge this buffer
+        size.
+       </para>
+
       </listitem>
      </varlistentry>
 
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 39ccfbb..3117f91 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -278,6 +278,14 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
      </row>
 
      <row>
+      <entry><structname>pg_stat_walwriter</><indexterm><primary>pg_stat_walwriter</primary></indexterm></entry>
+      <entry>One row only, showing statistics about the wal writer
+       process's activity. See <xref linkend="pg-stat-walwriter-view">
+       for details.
+     </entry>
+     </row>
+
+     <row>
       <entry><structname>pg_stat_database</><indexterm><primary>pg_stat_database</primary></indexterm></entry>
       <entry>One row per database, showing database-wide statistics. See
        <xref linkend="pg-stat-database-view"> for details.
@@ -735,6 +743,39 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    single row, containing global data for the cluster.
   </para>
 
+  <table id="pg-stat-walwriter-view" xreflabel="pg_stat_walwriter">
+   <title><structname>pg_stat_walwriter</structname> View</title>
+
+   <tgroup cols="3">
+    <thead>
+    <row>
+      <entry>Column</entry>
+      <entry>Type</entry>
+      <entry>Description</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry><structfield>dirty_writes</></entry>
+      <entry><type>bigint</type></entry>
+      <entry>Number of dirty writes, which means flushing wal buffers
+       because of its full.</entry>
+     </row>
+     <row>
+      <entry><structfield>stats_reset</></entry>
+      <entry><type>timestamp with time zone</type></entry>
+      <entry>Time at which these statistics were last reset</entry>
+     </row>
+    </tbody>
+    </tgroup>
+  </table>
+
+  <para>
+   The <structname>pg_stat_walwriter</structname> view will always have a
+   single row, containing global data for the cluster.
+  </para>
+
   <table id="pg-stat-database-view" xreflabel="pg_stat_database">
    <title><structname>pg_stat_database</structname> View</title>
    <tgroup cols="3">
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 2618c8d..0bf92fa 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1338,6 +1338,7 @@ AdvanceXLInsertBuffer(bool new_segment)
 				WriteRqst.Write = OldPageRqstPtr;
 				WriteRqst.Flush = 0;
 				XLogWrite(WriteRqst, false, false);
+				WalWriterStats.m_xlog_dirty_writes++;
 				LWLockRelease(WALWriteLock);
 				TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 			}
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 607a72f..40f0c34 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -671,6 +671,11 @@ CREATE VIEW pg_stat_bgwriter AS
         pg_stat_get_buf_alloc() AS buffers_alloc,
         pg_stat_get_bgwriter_stat_reset_time() AS stats_reset;
 
+CREATE VIEW pg_stat_walwriter AS
+    SELECT
+        pg_stat_get_xlog_dirty_writes() AS dirty_writes,
+        pg_stat_get_wal_stat_reset_time() AS stats_reset;
+
 CREATE VIEW pg_user_mappings AS
     SELECT
         U.oid       AS umid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index be3adf1..5be78c6 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -125,6 +125,15 @@ char	   *pgstat_stat_tmpname = NULL;
  */
 PgStat_MsgBgWriter BgWriterStats;
 
+/*
+ * WalWriter global statistics counter.
+ * Despite its name, this counter is actually used not only in walwriter,
+ * but also in each backend process to sum up xlog dirty writes.
+ * Those processes would increment this counter in each XLogWrite call,
+ * then send it to the stat collector process.
+ */
+PgStat_MsgWalWriter WalWriterStats;
+
 /* ----------
  * Local data
  * ----------
@@ -279,6 +288,7 @@ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
 static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
 static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
 static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
+static void pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
@@ -762,6 +772,9 @@ pgstat_report_stat(bool force)
 
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
+
+	/* Now, send wal buffer flush statistics */
+	pgstat_send_walwriter();
 }
 
 /*
@@ -1188,11 +1201,13 @@ pgstat_reset_shared_counters(const char *target)
 
 	if (strcmp(target, "bgwriter") == 0)
 		msg.m_resettarget = RESET_BGWRITER;
+	else if (strcmp(target, "walwriter") == 0)
+		msg.m_resettarget = RESET_WALWRITER;
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized reset target: \"%s\"", target),
-				 errhint("Target must be \"bgwriter\".")));
+				 errhint("Target must be \"bgwriter\" or \"walwriter\".")));
 
 	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER);
 	pgstat_send(&msg, sizeof(msg));
@@ -2988,6 +3003,38 @@ pgstat_send_bgwriter(void)
 	MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
 }
 
+/* ----------
+ * pgstat_send_walwriter() -
+ *
+ *		Send walwriter statistics to the collector
+ * ----------
+ */
+void
+pgstat_send_walwriter(void)
+{
+	/* We assume this initializes to zeroes */
+	static const PgStat_MsgBgWriter all_zeroes;
+
+	/*
+	 * This function can be called even if nothing at all has happened. In
+	 * this case, avoid sending a completely empty message to the stats
+	 * collector.
+	 */
+	if (memcmp(&WalWriterStats, &all_zeroes, sizeof(PgStat_MsgWalWriter)) == 0)
+		return;
+
+	/*
+	 * Prepare and send the message
+	 */
+	pgstat_setheader(&WalWriterStats.m_hdr, PGSTAT_MTYPE_WALWRITER);
+	pgstat_send(&WalWriterStats, sizeof(WalWriterStats));
+
+	/*
+	 * Clear out the statistics buffer, so it can be re-used.
+	 */
+	MemSet(&WalWriterStats, 0, sizeof(WalWriterStats));
+}
+
 
 /* ----------
  * PgstatCollectorMain() -
@@ -3209,6 +3256,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_WALWRITER:
+					pgstat_recv_walwriter((PgStat_MsgWalWriter *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_FUNCSTAT:
 					pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
 					break;
@@ -3638,7 +3689,8 @@ pgstat_read_statsfile(Oid onlydb, bool permanent)
 	 * Set the current timestamp (will be kept only in case we can't load an
 	 * existing statsfile).
 	 */
-	globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.stat_bgw_reset_timestamp = GetCurrentTimestamp();
+	globalStats.stat_wal_reset_timestamp = GetCurrentTimestamp();
 
 	/*
 	 * Try to open the status file. If it doesn't exist, the backends simply
@@ -4381,8 +4433,23 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len)
 	if (msg->m_resettarget == RESET_BGWRITER)
 	{
 		/* Reset the global background writer statistics for the cluster. */
-		memset(&globalStats, 0, sizeof(globalStats));
-		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+		globalStats.timed_checkpoints       = 0;
+		globalStats.requested_checkpoints   = 0;
+		globalStats.checkpoint_write_time   = 0;
+		globalStats.checkpoint_sync_time    = 0;
+		globalStats.buf_written_checkpoints = 0;
+		globalStats.buf_written_clean       = 0;
+		globalStats.maxwritten_clean        = 0;
+		globalStats.buf_written_backend     = 0;
+		globalStats.buf_fsync_backend       = 0;
+		globalStats.buf_alloc               = 0;
+		globalStats.stat_bgw_reset_timestamp = GetCurrentTimestamp();
+	}
+	else if (msg->m_resettarget == RESET_WALWRITER)
+	{
+		/* Reset the global walwriter statistics for the cluster. */
+		globalStats.xlog_dirty_writes = 0;
+		globalStats.stat_wal_reset_timestamp = GetCurrentTimestamp();
 	}
 
 	/*
@@ -4536,6 +4603,18 @@ pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
 }
 
 /* ----------
+ * pgstat_recv_walwriter() -
+ *
+ *	Process a WALWRITER message.
+ * ----------
+ */
+static void
+pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len)
+{
+	globalStats.xlog_dirty_writes += msg->m_xlog_dirty_writes;
+}
+
+/* ----------
  * pgstat_recv_recoveryconflict() -
  *
  *	Process a RECOVERYCONFLICT message.
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index c3e15ef..cd294fb 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -290,6 +290,8 @@ WalWriterMain(void)
 		else if (left_till_hibernate > 0)
 			left_till_hibernate--;
 
+		pgstat_send_walwriter();
+
 		/*
 		 * Sleep until we are signaled or WalWriterDelay has elapsed.  If we
 		 * haven't done anything useful for quite some time, lengthen the
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 7d4059f..fc25dda 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -97,6 +97,7 @@ extern Datum pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_alloc(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS);
 
 extern Datum pg_stat_get_xact_numscans(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_xact_tuples_returned(PG_FUNCTION_ARGS);
@@ -118,6 +119,8 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1443,7 +1446,7 @@ pg_stat_get_checkpoint_sync_time(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_reset_timestamp);
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_bgw_reset_timestamp);
 }
 
 Datum
@@ -1465,6 +1468,12 @@ pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)
 }
 
 Datum
+pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_wal_reset_timestamp);
+}
+
+Datum
 pg_stat_get_xact_numscans(PG_FUNCTION_ARGS)
 {
 	Oid			relid = PG_GETARG_OID(0);
@@ -1701,3 +1710,9 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(pgstat_fetch_global()->xlog_dirty_writes);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index f935eb1..d6edb5a 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2702,6 +2702,8 @@ DATA(insert OID = 3063 ( pg_stat_get_buf_fsync_backend PGNSP PGUID 12 1 0 0 0 f
 DESCR("statistics: number of backend buffer writes that did their own fsync");
 DATA(insert OID = 2859 ( pg_stat_get_buf_alloc			PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_alloc _null_ _null_ _null_ ));
 DESCR("statistics: number of buffer allocations");
+DATA(insert OID = 2860 ( pg_stat_get_wal_stat_reset_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_	pg_stat_get_wal_stat_reset_time _null_ _null_ _null_ ));
+DESCR("statistics: last reset for the wal");
 
 DATA(insert OID = 2978 (  pg_stat_get_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls");
@@ -2746,6 +2748,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3766 (  pg_stat_get_xlog_dirty_writes  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_writes _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 613c1c2..f71c538 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -45,6 +45,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_VACUUM,
 	PGSTAT_MTYPE_ANALYZE,
 	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WALWRITER,
 	PGSTAT_MTYPE_FUNCSTAT,
 	PGSTAT_MTYPE_FUNCPURGE,
 	PGSTAT_MTYPE_RECOVERYCONFLICT,
@@ -102,7 +103,8 @@ typedef struct PgStat_TableCounts
 /* Possible targets for resetting cluster-wide shared values */
 typedef enum PgStat_Shared_Reset_Target
 {
-	RESET_BGWRITER
+	RESET_BGWRITER,
+	RESET_WALWRITER
 } PgStat_Shared_Reset_Target;
 
 /* Possible object types for resetting single counters */
@@ -372,6 +374,17 @@ typedef struct PgStat_MsgBgWriter
 } PgStat_MsgBgWriter;
 
 /* ----------
+ * PgStat_MsgWalWriter			Sent by the walwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWalWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_xlog_dirty_writes;
+} PgStat_MsgWalWriter;
+
+/* ----------
  * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
  * ----------
  */
@@ -499,6 +512,7 @@ typedef union PgStat_Msg
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
 	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWalWriter msg_walwriter;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
@@ -622,7 +636,10 @@ typedef struct PgStat_GlobalStats
 	PgStat_Counter buf_written_backend;
 	PgStat_Counter buf_fsync_backend;
 	PgStat_Counter buf_alloc;
-	TimestampTz stat_reset_timestamp;
+	TimestampTz stat_bgw_reset_timestamp;
+
+	PgStat_Counter xlog_dirty_writes;
+	TimestampTz stat_wal_reset_timestamp;
 } PgStat_GlobalStats;
 
 
@@ -730,6 +747,8 @@ extern char *pgstat_stat_filename;
  */
 extern PgStat_MsgBgWriter BgWriterStats;
 
+extern PgStat_MsgWalWriter WalWriterStats;
+
 /*
  * Updated by pgstat_count_buffer_*_time macros
  */
@@ -858,6 +877,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 						  void *recdata, uint32 len);
 
 extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_walwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index a235571..1612cc0 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1305,6 +1305,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
  pg_stat_user_functions          | SELECT p.oid AS funcid, n.nspname AS schemaname, p.proname AS funcname, pg_stat_get_function_calls(p.oid) AS calls, pg_stat_get_function_total_time(p.oid) AS total_time, pg_stat_get_function_self_time(p.oid) AS self_time FROM (pg_proc p LEFT JOIN pg_namespace n ON ((n.oid = p.pronamespace))) WHERE ((p.prolang <> (12)::oid) AND (pg_stat_get_function_calls(p.oid) IS NOT NULL));
  pg_stat_user_indexes            | SELECT pg_stat_all_indexes.relid, pg_stat_all_indexes.indexrelid, pg_stat_all_indexes.schemaname, pg_stat_all_indexes.relname, pg_stat_all_indexes.indexrelname, pg_stat_all_indexes.idx_scan, pg_stat_all_indexes.idx_tup_read, pg_stat_all_indexes.idx_tup_fetch FROM pg_stat_all_indexes WHERE ((pg_stat_all_indexes.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_indexes.schemaname !~ '^pg_toast'::text));
  pg_stat_user_tables             | SELECT pg_stat_all_tables.relid, pg_stat_all_tables.schemaname, pg_stat_all_tables.relname, pg_stat_all_tables.seq_scan, pg_stat_all_tables.seq_tup_read, pg_stat_all_tables.idx_scan, pg_stat_all_tables.idx_tup_fetch, pg_stat_all_tables.n_tup_ins, pg_stat_all_tables.n_tup_upd, pg_stat_all_tables.n_tup_del, pg_stat_all_tables.n_tup_hot_upd, pg_stat_all_tables.n_live_tup, pg_stat_all_tables.n_dead_tup, pg_stat_all_tables.last_vacuum, pg_stat_all_tables.last_autovacuum, pg_stat_all_tables.last_analyze, pg_stat_all_tables.last_autoanalyze, pg_stat_all_tables.vacuum_count, pg_stat_all_tables.autovacuum_count, pg_stat_all_tables.analyze_count, pg_stat_all_tables.autoanalyze_count FROM pg_stat_all_tables WHERE ((pg_stat_all_tables.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_tables.schemaname !~ '^pg_toast'::text));
+ pg_stat_walwriter               | SELECT pg_stat_get_xlog_dirty_writes() AS dirty_writes, pg_stat_get_wal_stat_reset_time() AS stats_reset;
  pg_stat_xact_all_tables         | SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_xact_numscans(c.oid) AS seq_scan, pg_stat_get_xact_tuples_returned(c.oid) AS seq_tup_read, (sum(pg_stat_get_xact_numscans(i.indexrelid)))::bigint AS idx_scan, ((sum(pg_stat_get_xact_tuples_fetched(i.indexrelid)))::bigint + pg_stat_get_xact_tuples_fetched(c.oid)) AS idx_tup_fetch, pg_stat_get_xact_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_xact_tuples_updated(c.oid) AS n_tup_upd, pg_stat_get_xact_tuples_deleted(c.oid) AS n_tup_del, pg_stat_get_xact_tuples_hot_updated(c.oid) AS n_tup_hot_upd FROM ((pg_class c LEFT JOIN pg_index i ON ((c.oid = i.indrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = ANY (ARRAY['r'::"char", 't'::"char"])) GROUP BY c.oid, n.nspname, c.relname;
  pg_stat_xact_sys_tables         | SELECT pg_stat_xact_all_tables.relid, pg_stat_xact_all_tables.schemaname, pg_stat_xact_all_tables.relname, pg_stat_xact_all_tables.seq_scan, pg_stat_xact_all_tables.seq_tup_read, pg_stat_xact_all_tables.idx_scan, pg_stat_xact_all_tables.idx_tup_fetch, pg_stat_xact_all_tables.n_tup_ins, pg_stat_xact_all_tables.n_tup_upd, pg_stat_xact_all_tables.n_tup_del, pg_stat_xact_all_tables.n_tup_hot_upd FROM pg_stat_xact_all_tables WHERE ((pg_stat_xact_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_xact_all_tables.schemaname ~ '^pg_toast'::text));
  pg_stat_xact_user_functions     | SELECT p.oid AS funcid, n.nspname AS schemaname, p.proname AS funcname, pg_stat_get_xact_function_calls(p.oid) AS calls, pg_stat_get_xact_function_total_time(p.oid) AS total_time, pg_stat_get_xact_function_self_time(p.oid) AS self_time FROM (pg_proc p LEFT JOIN pg_namespace n ON ((n.oid = p.pronamespace))) WHERE ((p.prolang <> (12)::oid) AND (pg_stat_get_xact_function_calls(p.oid) IS NOT NULL));
@@ -1339,7 +1340,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
  shoelace_obsolete               | SELECT shoelace.sl_name, shoelace.sl_avail, shoelace.sl_color, shoelace.sl_len, shoelace.sl_unit, shoelace.sl_len_cm FROM shoelace WHERE (NOT (EXISTS (SELECT shoe.shoename FROM shoe WHERE (shoe.slcolor = shoelace.sl_color))));
  street                          | SELECT r.name, r.thepath, c.cname FROM ONLY road r, real_city c WHERE (c.outline ## r.thepath);
  toyemp                          | SELECT emp.name, emp.age, emp.location, (12 * emp.salary) AS annualsal FROM emp;
-(60 rows)
+(61 rows)
 
 SELECT tablename, rulename, definition FROM pg_rules
 	ORDER BY tablename, rulename;

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 23ebc11..cdced7f 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1878,6 +1878,13 @@ include 'filename'
         results in most cases.
        </para>
 
+       <para>
+        When you see pg_stat_walwriter.dirty_write, which means number
+        of buffer flushing at buffer full, is continuously increasing
+        in your running server, you may need to enlarge this buffer
+        size.
+       </para>
+
       </listitem>
      </varlistentry>
 
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 4ec6981..15d9202 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -278,6 +278,14 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
      </row>
 
      <row>
+      <entry><structname>pg_stat_walwriter</><indexterm><primary>pg_stat_walwriter</primary></indexterm></entry>
+      <entry>One row only, showing statistics about the wal writer
+       process's activity. See <xref linkend="pg-stat-walwriter-view">
+       for details.
+     </entry>
+     </row>
+
+     <row>
       <entry><structname>pg_stat_database</><indexterm><primary>pg_stat_database</primary></indexterm></entry>
       <entry>One row per database, showing database-wide statistics. See
        <xref linkend="pg-stat-database-view"> for details.
@@ -735,6 +743,39 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    single row, containing global data for the cluster.
   </para>
 
+  <table id="pg-stat-walwriter-view" xreflabel="pg_stat_walwriter">
+   <title><structname>pg_stat_walwriter</structname> View</title>
+
+   <tgroup cols="3">
+    <thead>
+    <row>
+      <entry>Column</entry>
+      <entry>Type</entry>
+      <entry>Description</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry><structfield>dirty_writes</></entry>
+      <entry><type>bigint</type></entry>
+      <entry>Number of dirty writes, which means flushing wal buffers
+       because of its full.</entry>
+     </row>
+     <row>
+      <entry><structfield>stats_reset</></entry>
+      <entry><type>timestamp with time zone</type></entry>
+      <entry>Time at which these statistics were last reset</entry>
+     </row>
+    </tbody>
+    </tgroup>
+  </table>
+
+  <para>
+   The <structname>pg_stat_walwriter</structname> view will always have a
+   single row, containing global data for the cluster.
+  </para>
+
   <table id="pg-stat-database-view" xreflabel="pg_stat_database">
    <title><structname>pg_stat_database</structname> View</title>
    <tgroup cols="3">
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index dc47c47..d0e85c9 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2467,6 +2467,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, bool opportunistic)
 					WriteRqst.Write = OldPageRqstPtr;
 					WriteRqst.Flush = 0;
 					XLogWrite(WriteRqst, false);
+					WalWriterStats.m_xlog_dirty_writes++;
 					LWLockRelease(WALWriteLock);
 					TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 				}
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 575a40f..12a2ed0 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -686,6 +686,11 @@ CREATE VIEW pg_stat_bgwriter AS
         pg_stat_get_buf_alloc() AS buffers_alloc,
         pg_stat_get_bgwriter_stat_reset_time() AS stats_reset;
 
+CREATE VIEW pg_stat_walwriter AS
+    SELECT
+        pg_stat_get_xlog_dirty_writes() AS dirty_writes,
+        pg_stat_get_wal_stat_reset_time() AS stats_reset;
+
 CREATE VIEW pg_user_mappings AS
     SELECT
         U.oid       AS umid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index b5ce2f6..8c56af5 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -129,6 +129,14 @@ char	   *pgstat_stat_tmpname = NULL;
  */
 PgStat_MsgBgWriter BgWriterStats;
 
+/*
+ * WalWriter statistics counter.
+ * This counter is incremented by each XLogWrite call,
+ * both in the wal writer process and each backend.
+ * And then, sent to the stat collector process.
+ */
+PgStat_MsgWalWriter WalWriterStats;
+
 /* ----------
  * Local data
  * ----------
@@ -293,6 +301,7 @@ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
 static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
 static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
 static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
+static void pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
@@ -820,6 +829,9 @@ pgstat_report_stat(bool force)
 
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
+
+	/* Now, send wal buffer flush statistics */
+	pgstat_send_walwriter();
 }
 
 /*
@@ -1249,11 +1261,13 @@ pgstat_reset_shared_counters(const char *target)
 
 	if (strcmp(target, "bgwriter") == 0)
 		msg.m_resettarget = RESET_BGWRITER;
+	else if (strcmp(target, "walwriter") == 0)
+		msg.m_resettarget = RESET_WALWRITER;
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized reset target: \"%s\"", target),
-				 errhint("Target must be \"bgwriter\".")));
+				 errhint("Target must be \"bgwriter\" or \"walwriter\".")));
 
 	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER);
 	pgstat_send(&msg, sizeof(msg));
@@ -3055,6 +3069,38 @@ pgstat_send_bgwriter(void)
 	MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
 }
 
+/* ----------
+ * pgstat_send_walwriter() -
+ *
+ *		Send walwriter statistics to the collector
+ * ----------
+ */
+void
+pgstat_send_walwriter(void)
+{
+	/* We assume this initializes to zeroes */
+	static const PgStat_MsgBgWriter all_zeroes;
+
+	/*
+	 * This function can be called even if nothing at all has happened. In
+	 * this case, avoid sending a completely empty message to the stats
+	 * collector.
+	 */
+	if (memcmp(&WalWriterStats, &all_zeroes, sizeof(PgStat_MsgWalWriter)) == 0)
+		return;
+
+	/*
+	 * Prepare and send the message
+	 */
+	pgstat_setheader(&WalWriterStats.m_hdr, PGSTAT_MTYPE_WALWRITER);
+	pgstat_send(&WalWriterStats, sizeof(WalWriterStats));
+
+	/*
+	 * Clear out the statistics buffer, so it can be re-used.
+	 */
+	MemSet(&WalWriterStats, 0, sizeof(WalWriterStats));
+}
+
 
 /* ----------
  * PgstatCollectorMain() -
@@ -3270,6 +3316,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_WALWRITER:
+					pgstat_recv_walwriter((PgStat_MsgWalWriter *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_FUNCSTAT:
 					pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
 					break;
@@ -3825,7 +3875,8 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 	 * Set the current timestamp (will be kept only in case we can't load an
 	 * existing statsfile).
 	 */
-	globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.bgWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.walWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
 
 	/*
 	 * Try to open the stats file. If it doesn't exist, the backends simply
@@ -4723,8 +4774,23 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len)
 	if (msg->m_resettarget == RESET_BGWRITER)
 	{
 		/* Reset the global background writer statistics for the cluster. */
-		memset(&globalStats, 0, sizeof(globalStats));
-		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+		globalStats.bgWriterGlobalStats.timed_checkpoints       = 0;
+		globalStats.bgWriterGlobalStats.requested_checkpoints   = 0;
+		globalStats.bgWriterGlobalStats.checkpoint_write_time   = 0;
+		globalStats.bgWriterGlobalStats.checkpoint_sync_time    = 0;
+		globalStats.bgWriterGlobalStats.buf_written_checkpoints = 0;
+		globalStats.bgWriterGlobalStats.buf_written_clean       = 0;
+		globalStats.bgWriterGlobalStats.maxwritten_clean        = 0;
+		globalStats.bgWriterGlobalStats.buf_written_backend     = 0;
+		globalStats.bgWriterGlobalStats.buf_fsync_backend       = 0;
+		globalStats.bgWriterGlobalStats.buf_alloc               = 0;
+		globalStats.bgWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	}
+	else if (msg->m_resettarget == RESET_WALWRITER)
+	{
+		/* Reset the global walwriter statistics for the cluster. */
+		globalStats.walWriterGlobalStats.xlog_dirty_writes = 0;
+		globalStats.walWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
 	}
 
 	/*
@@ -4865,16 +4931,28 @@ pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len)
 static void
 pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
 {
-	globalStats.timed_checkpoints += msg->m_timed_checkpoints;
-	globalStats.requested_checkpoints += msg->m_requested_checkpoints;
-	globalStats.checkpoint_write_time += msg->m_checkpoint_write_time;
-	globalStats.checkpoint_sync_time += msg->m_checkpoint_sync_time;
-	globalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
-	globalStats.buf_written_clean += msg->m_buf_written_clean;
-	globalStats.maxwritten_clean += msg->m_maxwritten_clean;
-	globalStats.buf_written_backend += msg->m_buf_written_backend;
-	globalStats.buf_fsync_backend += msg->m_buf_fsync_backend;
-	globalStats.buf_alloc += msg->m_buf_alloc;
+	globalStats.bgWriterGlobalStats.timed_checkpoints += msg->m_timed_checkpoints;
+	globalStats.bgWriterGlobalStats.requested_checkpoints += msg->m_requested_checkpoints;
+	globalStats.bgWriterGlobalStats.checkpoint_write_time += msg->m_checkpoint_write_time;
+	globalStats.bgWriterGlobalStats.checkpoint_sync_time += msg->m_checkpoint_sync_time;
+	globalStats.bgWriterGlobalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
+	globalStats.bgWriterGlobalStats.buf_written_clean += msg->m_buf_written_clean;
+	globalStats.bgWriterGlobalStats.maxwritten_clean += msg->m_maxwritten_clean;
+	globalStats.bgWriterGlobalStats.buf_written_backend += msg->m_buf_written_backend;
+	globalStats.bgWriterGlobalStats.buf_fsync_backend += msg->m_buf_fsync_backend;
+	globalStats.bgWriterGlobalStats.buf_alloc += msg->m_buf_alloc;
+}
+
+/* ----------
+ * pgstat_recv_walwriter() -
+ *
+ *	Process a WALWRITER message.
+ * ----------
+ */
+static void
+pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len)
+{
+	globalStats.walWriterGlobalStats.xlog_dirty_writes += msg->m_xlog_dirty_writes;
 }
 
 /* ----------
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 8359da6..dedec0d 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -290,6 +290,8 @@ WalWriterMain(void)
 		else if (left_till_hibernate > 0)
 			left_till_hibernate--;
 
+		pgstat_send_walwriter();
+
 		/*
 		 * Sleep until we are signaled or WalWriterDelay has elapsed.  If we
 		 * haven't done anything useful for quite some time, lengthen the
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 0533cd6..df9f1d8 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -98,6 +98,7 @@ extern Datum pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_alloc(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS);
 
 extern Datum pg_stat_get_xact_numscans(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_xact_tuples_returned(PG_FUNCTION_ARGS);
@@ -119,6 +120,8 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1409,69 +1412,75 @@ pg_stat_get_db_blk_write_time(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->timed_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.timed_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_requested_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->requested_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.requested_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_buf_written_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_buf_written_clean(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_clean);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_clean);
 }
 
 Datum
 pg_stat_get_bgwriter_maxwritten_clean(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->maxwritten_clean);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.maxwritten_clean);
 }
 
 Datum
 pg_stat_get_checkpoint_write_time(PG_FUNCTION_ARGS)
 {
 	/* time is already in msec, just convert to double for presentation */
-	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->checkpoint_write_time);
+	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->bgWriterGlobalStats.checkpoint_write_time);
 }
 
 Datum
 pg_stat_get_checkpoint_sync_time(PG_FUNCTION_ARGS)
 {
 	/* time is already in msec, just convert to double for presentation */
-	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->checkpoint_sync_time);
+	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->bgWriterGlobalStats.checkpoint_sync_time);
 }
 
 Datum
 pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_reset_timestamp);
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->bgWriterGlobalStats.stat_reset_timestamp);
 }
 
 Datum
 pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_backend);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_backend);
 }
 
 Datum
 pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_fsync_backend);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_fsync_backend);
 }
 
 Datum
 pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_alloc);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_alloc);
+}
+
+Datum
+pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->walWriterGlobalStats.stat_reset_timestamp);
 }
 
 Datum
@@ -1711,3 +1720,9 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(pgstat_fetch_global()->walWriterGlobalStats.xlog_dirty_writes);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index f03dd0b..add47dc 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2709,6 +2709,8 @@ DATA(insert OID = 3063 ( pg_stat_get_buf_fsync_backend PGNSP PGUID 12 1 0 0 0 f
 DESCR("statistics: number of backend buffer writes that did their own fsync");
 DATA(insert OID = 2859 ( pg_stat_get_buf_alloc			PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_alloc _null_ _null_ _null_ ));
 DESCR("statistics: number of buffer allocations");
+DATA(insert OID = 2860 ( pg_stat_get_wal_stat_reset_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_	pg_stat_get_wal_stat_reset_time _null_ _null_ _null_ ));
+DESCR("statistics: last reset for the wal");
 
 DATA(insert OID = 2978 (  pg_stat_get_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls");
@@ -2753,6 +2755,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3766 (  pg_stat_get_xlog_dirty_writes  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_writes _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fb242e4..1213964 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -45,6 +45,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_VACUUM,
 	PGSTAT_MTYPE_ANALYZE,
 	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WALWRITER,
 	PGSTAT_MTYPE_FUNCSTAT,
 	PGSTAT_MTYPE_FUNCPURGE,
 	PGSTAT_MTYPE_RECOVERYCONFLICT,
@@ -102,7 +103,8 @@ typedef struct PgStat_TableCounts
 /* Possible targets for resetting cluster-wide shared values */
 typedef enum PgStat_Shared_Reset_Target
 {
-	RESET_BGWRITER
+	RESET_BGWRITER,
+	RESET_WALWRITER
 } PgStat_Shared_Reset_Target;
 
 /* Possible object types for resetting single counters */
@@ -373,6 +375,17 @@ typedef struct PgStat_MsgBgWriter
 } PgStat_MsgBgWriter;
 
 /* ----------
+ * PgStat_MsgWalWriter			Sent by the walwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWalWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_xlog_dirty_writes;
+} PgStat_MsgWalWriter;
+
+/* ----------
  * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
  * ----------
  */
@@ -500,6 +513,7 @@ typedef union PgStat_Msg
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
 	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWalWriter msg_walwriter;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
@@ -608,12 +622,8 @@ typedef struct PgStat_StatFuncEntry
 } PgStat_StatFuncEntry;
 
 
-/*
- * Global statistics kept in the stats collector
- */
-typedef struct PgStat_GlobalStats
+typedef struct PgStat_BgWriterGlobalStats
 {
-	TimestampTz stats_timestamp;	/* time of stats file update */
 	PgStat_Counter timed_checkpoints;
 	PgStat_Counter requested_checkpoints;
 	PgStat_Counter checkpoint_write_time;		/* times in milliseconds */
@@ -625,6 +635,22 @@ typedef struct PgStat_GlobalStats
 	PgStat_Counter buf_fsync_backend;
 	PgStat_Counter buf_alloc;
 	TimestampTz stat_reset_timestamp;
+} PgStat_BgWriterGlobalStats;
+
+typedef struct PgStat_WalWriterGlobalStats
+{
+	PgStat_Counter xlog_dirty_writes;
+	TimestampTz stat_reset_timestamp;
+} PgStat_WalWriterGlobalStats;
+
+/*
+ * Global statistics kept in the stats collector
+ */
+typedef struct PgStat_GlobalStats
+{
+	TimestampTz stats_timestamp;    /* time of stats file update */
+	PgStat_BgWriterGlobalStats bgWriterGlobalStats;
+	PgStat_WalWriterGlobalStats walWriterGlobalStats;
 } PgStat_GlobalStats;
 
 
@@ -733,6 +759,8 @@ extern char *pgstat_stat_filename;
  */
 extern PgStat_MsgBgWriter BgWriterStats;
 
+extern PgStat_MsgWalWriter WalWriterStats;
+
 /*
  * Updated by pgstat_count_buffer_*_time macros
  */
@@ -861,6 +889,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 						  void *recdata, uint32 len);
 
 extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_walwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 8f24c51..4074c61 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1775,6 +1775,8 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
                                  |     pg_stat_all_tables.autoanalyze_count                                                                                                                                                                       +
                                  |    FROM pg_stat_all_tables                                                                                                                                                                                     +
                                  |   WHERE ((pg_stat_all_tables.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_tables.schemaname !~ '^pg_toast'::text));
+ pg_stat_walwriter               |  SELECT pg_stat_get_xlog_dirty_writes() AS dirty_writes,                                                                                                                                                       +
+                                 |     pg_stat_get_wal_stat_reset_time() AS stats_reset;
  pg_stat_xact_all_tables         |  SELECT c.oid AS relid,                                                                                                                                                                                        +
                                  |     n.nspname AS schemaname,                                                                                                                                                                                   +
                                  |     c.relname,                                                                                                                                                                                                 +
@@ -2142,7 +2144,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
                                  |    FROM tv;
  tvvmv                           |  SELECT tvvm.grandtot                                                                                                                                                                                          +
                                  |    FROM tvvm;
-(64 rows)
+(65 rows)
 
 SELECT tablename, rulename, definition FROM pg_rules
 	ORDER BY tablename, rulename;

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 23ebc11..cdced7f 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1878,6 +1878,13 @@ include 'filename'
         results in most cases.
        </para>
 
+       <para>
+        When you see pg_stat_walwriter.dirty_write, which means number
+        of buffer flushing at buffer full, is continuously increasing
+        in your running server, you may need to enlarge this buffer
+        size.
+       </para>
+
       </listitem>
      </varlistentry>
 
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 4ec6981..15d9202 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -278,6 +278,14 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
      </row>
 
      <row>
+      <entry><structname>pg_stat_walwriter</><indexterm><primary>pg_stat_walwriter</primary></indexterm></entry>
+      <entry>One row only, showing statistics about the wal writer
+       process's activity. See <xref linkend="pg-stat-walwriter-view">
+       for details.
+     </entry>
+     </row>
+
+     <row>
       <entry><structname>pg_stat_database</><indexterm><primary>pg_stat_database</primary></indexterm></entry>
       <entry>One row per database, showing database-wide statistics. See
        <xref linkend="pg-stat-database-view"> for details.
@@ -735,6 +743,39 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    single row, containing global data for the cluster.
   </para>
 
+  <table id="pg-stat-walwriter-view" xreflabel="pg_stat_walwriter">
+   <title><structname>pg_stat_walwriter</structname> View</title>
+
+   <tgroup cols="3">
+    <thead>
+    <row>
+      <entry>Column</entry>
+      <entry>Type</entry>
+      <entry>Description</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry><structfield>dirty_writes</></entry>
+      <entry><type>bigint</type></entry>
+      <entry>Number of dirty writes, which means flushing wal buffers
+       because of its full.</entry>
+     </row>
+     <row>
+      <entry><structfield>stats_reset</></entry>
+      <entry><type>timestamp with time zone</type></entry>
+      <entry>Time at which these statistics were last reset</entry>
+     </row>
+    </tbody>
+    </tgroup>
+  </table>
+
+  <para>
+   The <structname>pg_stat_walwriter</structname> view will always have a
+   single row, containing global data for the cluster.
+  </para>
+
   <table id="pg-stat-database-view" xreflabel="pg_stat_database">
    <title><structname>pg_stat_database</structname> View</title>
    <tgroup cols="3">
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index dc47c47..d0e85c9 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2467,6 +2467,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, bool opportunistic)
 					WriteRqst.Write = OldPageRqstPtr;
 					WriteRqst.Flush = 0;
 					XLogWrite(WriteRqst, false);
+					WalWriterStats.m_xlog_dirty_writes++;
 					LWLockRelease(WALWriteLock);
 					TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 				}
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 575a40f..12a2ed0 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -686,6 +686,11 @@ CREATE VIEW pg_stat_bgwriter AS
         pg_stat_get_buf_alloc() AS buffers_alloc,
         pg_stat_get_bgwriter_stat_reset_time() AS stats_reset;
 
+CREATE VIEW pg_stat_walwriter AS
+    SELECT
+        pg_stat_get_xlog_dirty_writes() AS dirty_writes,
+        pg_stat_get_wal_stat_reset_time() AS stats_reset;
+
 CREATE VIEW pg_user_mappings AS
     SELECT
         U.oid       AS umid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index b5ce2f6..8c56af5 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -129,6 +129,14 @@ char	   *pgstat_stat_tmpname = NULL;
  */
 PgStat_MsgBgWriter BgWriterStats;
 
+/*
+ * WalWriter statistics counter.
+ * This counter is incremented by each XLogWrite call,
+ * both in the wal writer process and each backend.
+ * And then, sent to the stat collector process.
+ */
+PgStat_MsgWalWriter WalWriterStats;
+
 /* ----------
  * Local data
  * ----------
@@ -293,6 +301,7 @@ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
 static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
 static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
 static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
+static void pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
@@ -820,6 +829,9 @@ pgstat_report_stat(bool force)
 
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
+
+	/* Now, send wal buffer flush statistics */
+	pgstat_send_walwriter();
 }
 
 /*
@@ -1249,11 +1261,13 @@ pgstat_reset_shared_counters(const char *target)
 
 	if (strcmp(target, "bgwriter") == 0)
 		msg.m_resettarget = RESET_BGWRITER;
+	else if (strcmp(target, "walwriter") == 0)
+		msg.m_resettarget = RESET_WALWRITER;
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized reset target: \"%s\"", target),
-				 errhint("Target must be \"bgwriter\".")));
+				 errhint("Target must be \"bgwriter\" or \"walwriter\".")));
 
 	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER);
 	pgstat_send(&msg, sizeof(msg));
@@ -3055,6 +3069,38 @@ pgstat_send_bgwriter(void)
 	MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
 }
 
+/* ----------
+ * pgstat_send_walwriter() -
+ *
+ *		Send walwriter statistics to the collector
+ * ----------
+ */
+void
+pgstat_send_walwriter(void)
+{
+	/* We assume this initializes to zeroes */
+	static const PgStat_MsgBgWriter all_zeroes;
+
+	/*
+	 * This function can be called even if nothing at all has happened. In
+	 * this case, avoid sending a completely empty message to the stats
+	 * collector.
+	 */
+	if (memcmp(&WalWriterStats, &all_zeroes, sizeof(PgStat_MsgWalWriter)) == 0)
+		return;
+
+	/*
+	 * Prepare and send the message
+	 */
+	pgstat_setheader(&WalWriterStats.m_hdr, PGSTAT_MTYPE_WALWRITER);
+	pgstat_send(&WalWriterStats, sizeof(WalWriterStats));
+
+	/*
+	 * Clear out the statistics buffer, so it can be re-used.
+	 */
+	MemSet(&WalWriterStats, 0, sizeof(WalWriterStats));
+}
+
 
 /* ----------
  * PgstatCollectorMain() -
@@ -3270,6 +3316,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_WALWRITER:
+					pgstat_recv_walwriter((PgStat_MsgWalWriter *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_FUNCSTAT:
 					pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
 					break;
@@ -3825,7 +3875,8 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 	 * Set the current timestamp (will be kept only in case we can't load an
 	 * existing statsfile).
 	 */
-	globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.bgWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.walWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
 
 	/*
 	 * Try to open the stats file. If it doesn't exist, the backends simply
@@ -4723,8 +4774,23 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len)
 	if (msg->m_resettarget == RESET_BGWRITER)
 	{
 		/* Reset the global background writer statistics for the cluster. */
-		memset(&globalStats, 0, sizeof(globalStats));
-		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+		globalStats.bgWriterGlobalStats.timed_checkpoints       = 0;
+		globalStats.bgWriterGlobalStats.requested_checkpoints   = 0;
+		globalStats.bgWriterGlobalStats.checkpoint_write_time   = 0;
+		globalStats.bgWriterGlobalStats.checkpoint_sync_time    = 0;
+		globalStats.bgWriterGlobalStats.buf_written_checkpoints = 0;
+		globalStats.bgWriterGlobalStats.buf_written_clean       = 0;
+		globalStats.bgWriterGlobalStats.maxwritten_clean        = 0;
+		globalStats.bgWriterGlobalStats.buf_written_backend     = 0;
+		globalStats.bgWriterGlobalStats.buf_fsync_backend       = 0;
+		globalStats.bgWriterGlobalStats.buf_alloc               = 0;
+		globalStats.bgWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	}
+	else if (msg->m_resettarget == RESET_WALWRITER)
+	{
+		/* Reset the global walwriter statistics for the cluster. */
+		globalStats.walWriterGlobalStats.xlog_dirty_writes = 0;
+		globalStats.walWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
 	}
 
 	/*
@@ -4865,16 +4931,28 @@ pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len)
 static void
 pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
 {
-	globalStats.timed_checkpoints += msg->m_timed_checkpoints;
-	globalStats.requested_checkpoints += msg->m_requested_checkpoints;
-	globalStats.checkpoint_write_time += msg->m_checkpoint_write_time;
-	globalStats.checkpoint_sync_time += msg->m_checkpoint_sync_time;
-	globalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
-	globalStats.buf_written_clean += msg->m_buf_written_clean;
-	globalStats.maxwritten_clean += msg->m_maxwritten_clean;
-	globalStats.buf_written_backend += msg->m_buf_written_backend;
-	globalStats.buf_fsync_backend += msg->m_buf_fsync_backend;
-	globalStats.buf_alloc += msg->m_buf_alloc;
+	globalStats.bgWriterGlobalStats.timed_checkpoints += msg->m_timed_checkpoints;
+	globalStats.bgWriterGlobalStats.requested_checkpoints += msg->m_requested_checkpoints;
+	globalStats.bgWriterGlobalStats.checkpoint_write_time += msg->m_checkpoint_write_time;
+	globalStats.bgWriterGlobalStats.checkpoint_sync_time += msg->m_checkpoint_sync_time;
+	globalStats.bgWriterGlobalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
+	globalStats.bgWriterGlobalStats.buf_written_clean += msg->m_buf_written_clean;
+	globalStats.bgWriterGlobalStats.maxwritten_clean += msg->m_maxwritten_clean;
+	globalStats.bgWriterGlobalStats.buf_written_backend += msg->m_buf_written_backend;
+	globalStats.bgWriterGlobalStats.buf_fsync_backend += msg->m_buf_fsync_backend;
+	globalStats.bgWriterGlobalStats.buf_alloc += msg->m_buf_alloc;
+}
+
+/* ----------
+ * pgstat_recv_walwriter() -
+ *
+ *	Process a WALWRITER message.
+ * ----------
+ */
+static void
+pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len)
+{
+	globalStats.walWriterGlobalStats.xlog_dirty_writes += msg->m_xlog_dirty_writes;
 }
 
 /* ----------
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 8359da6..dedec0d 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -290,6 +290,8 @@ WalWriterMain(void)
 		else if (left_till_hibernate > 0)
 			left_till_hibernate--;
 
+		pgstat_send_walwriter();
+
 		/*
 		 * Sleep until we are signaled or WalWriterDelay has elapsed.  If we
 		 * haven't done anything useful for quite some time, lengthen the
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 0533cd6..df9f1d8 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -98,6 +98,7 @@ extern Datum pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_alloc(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS);
 
 extern Datum pg_stat_get_xact_numscans(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_xact_tuples_returned(PG_FUNCTION_ARGS);
@@ -119,6 +120,8 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1409,69 +1412,75 @@ pg_stat_get_db_blk_write_time(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->timed_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.timed_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_requested_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->requested_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.requested_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_buf_written_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_buf_written_clean(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_clean);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_clean);
 }
 
 Datum
 pg_stat_get_bgwriter_maxwritten_clean(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->maxwritten_clean);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.maxwritten_clean);
 }
 
 Datum
 pg_stat_get_checkpoint_write_time(PG_FUNCTION_ARGS)
 {
 	/* time is already in msec, just convert to double for presentation */
-	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->checkpoint_write_time);
+	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->bgWriterGlobalStats.checkpoint_write_time);
 }
 
 Datum
 pg_stat_get_checkpoint_sync_time(PG_FUNCTION_ARGS)
 {
 	/* time is already in msec, just convert to double for presentation */
-	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->checkpoint_sync_time);
+	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->bgWriterGlobalStats.checkpoint_sync_time);
 }
 
 Datum
 pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_reset_timestamp);
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->bgWriterGlobalStats.stat_reset_timestamp);
 }
 
 Datum
 pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_backend);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_backend);
 }
 
 Datum
 pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_fsync_backend);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_fsync_backend);
 }
 
 Datum
 pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_alloc);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_alloc);
+}
+
+Datum
+pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->walWriterGlobalStats.stat_reset_timestamp);
 }
 
 Datum
@@ -1711,3 +1720,9 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(pgstat_fetch_global()->walWriterGlobalStats.xlog_dirty_writes);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index f03dd0b..b1f9c54 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2709,6 +2709,8 @@ DATA(insert OID = 3063 ( pg_stat_get_buf_fsync_backend PGNSP PGUID 12 1 0 0 0 f
 DESCR("statistics: number of backend buffer writes that did their own fsync");
 DATA(insert OID = 2859 ( pg_stat_get_buf_alloc			PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_alloc _null_ _null_ _null_ ));
 DESCR("statistics: number of buffer allocations");
+DATA(insert OID = 3178 ( pg_stat_get_wal_stat_reset_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_	pg_stat_get_wal_stat_reset_time _null_ _null_ _null_ ));
+DESCR("statistics: last reset for the wal");
 
 DATA(insert OID = 2978 (  pg_stat_get_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls");
@@ -2753,6 +2755,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3179 (  pg_stat_get_xlog_dirty_writes  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_writes _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fb242e4..1213964 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -45,6 +45,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_VACUUM,
 	PGSTAT_MTYPE_ANALYZE,
 	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WALWRITER,
 	PGSTAT_MTYPE_FUNCSTAT,
 	PGSTAT_MTYPE_FUNCPURGE,
 	PGSTAT_MTYPE_RECOVERYCONFLICT,
@@ -102,7 +103,8 @@ typedef struct PgStat_TableCounts
 /* Possible targets for resetting cluster-wide shared values */
 typedef enum PgStat_Shared_Reset_Target
 {
-	RESET_BGWRITER
+	RESET_BGWRITER,
+	RESET_WALWRITER
 } PgStat_Shared_Reset_Target;
 
 /* Possible object types for resetting single counters */
@@ -373,6 +375,17 @@ typedef struct PgStat_MsgBgWriter
 } PgStat_MsgBgWriter;
 
 /* ----------
+ * PgStat_MsgWalWriter			Sent by the walwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWalWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_xlog_dirty_writes;
+} PgStat_MsgWalWriter;
+
+/* ----------
  * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
  * ----------
  */
@@ -500,6 +513,7 @@ typedef union PgStat_Msg
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
 	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWalWriter msg_walwriter;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
@@ -608,12 +622,8 @@ typedef struct PgStat_StatFuncEntry
 } PgStat_StatFuncEntry;
 
 
-/*
- * Global statistics kept in the stats collector
- */
-typedef struct PgStat_GlobalStats
+typedef struct PgStat_BgWriterGlobalStats
 {
-	TimestampTz stats_timestamp;	/* time of stats file update */
 	PgStat_Counter timed_checkpoints;
 	PgStat_Counter requested_checkpoints;
 	PgStat_Counter checkpoint_write_time;		/* times in milliseconds */
@@ -625,6 +635,22 @@ typedef struct PgStat_GlobalStats
 	PgStat_Counter buf_fsync_backend;
 	PgStat_Counter buf_alloc;
 	TimestampTz stat_reset_timestamp;
+} PgStat_BgWriterGlobalStats;
+
+typedef struct PgStat_WalWriterGlobalStats
+{
+	PgStat_Counter xlog_dirty_writes;
+	TimestampTz stat_reset_timestamp;
+} PgStat_WalWriterGlobalStats;
+
+/*
+ * Global statistics kept in the stats collector
+ */
+typedef struct PgStat_GlobalStats
+{
+	TimestampTz stats_timestamp;    /* time of stats file update */
+	PgStat_BgWriterGlobalStats bgWriterGlobalStats;
+	PgStat_WalWriterGlobalStats walWriterGlobalStats;
 } PgStat_GlobalStats;
 
 
@@ -733,6 +759,8 @@ extern char *pgstat_stat_filename;
  */
 extern PgStat_MsgBgWriter BgWriterStats;
 
+extern PgStat_MsgWalWriter WalWriterStats;
+
 /*
  * Updated by pgstat_count_buffer_*_time macros
  */
@@ -861,6 +889,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 						  void *recdata, uint32 len);
 
 extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_walwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 8f24c51..4074c61 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1775,6 +1775,8 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
                                  |     pg_stat_all_tables.autoanalyze_count                                                                                                                                                                       +
                                  |    FROM pg_stat_all_tables                                                                                                                                                                                     +
                                  |   WHERE ((pg_stat_all_tables.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_tables.schemaname !~ '^pg_toast'::text));
+ pg_stat_walwriter               |  SELECT pg_stat_get_xlog_dirty_writes() AS dirty_writes,                                                                                                                                                       +
+                                 |     pg_stat_get_wal_stat_reset_time() AS stats_reset;
  pg_stat_xact_all_tables         |  SELECT c.oid AS relid,                                                                                                                                                                                        +
                                  |     n.nspname AS schemaname,                                                                                                                                                                                   +
                                  |     c.relname,                                                                                                                                                                                                 +
@@ -2142,7 +2144,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
                                  |    FROM tv;
  tvvmv                           |  SELECT tvvm.grandtot                                                                                                                                                                                          +
                                  |    FROM tvvm;
-(64 rows)
+(65 rows)
 
 SELECT tablename, rulename, definition FROM pg_rules
 	ORDER BY tablename, rulename;

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 23ebc11..cdced7f 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1878,6 +1878,13 @@ include 'filename'
         results in most cases.
        </para>
 
+       <para>
+        When you see pg_stat_walwriter.dirty_write, which means number
+        of buffer flushing at buffer full, is continuously increasing
+        in your running server, you may need to enlarge this buffer
+        size.
+       </para>
+
       </listitem>
      </varlistentry>
 
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 4ec6981..15d9202 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -278,6 +278,14 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
      </row>
 
      <row>
+      <entry><structname>pg_stat_walwriter</><indexterm><primary>pg_stat_walwriter</primary></indexterm></entry>
+      <entry>One row only, showing statistics about the wal writer
+       process's activity. See <xref linkend="pg-stat-walwriter-view">
+       for details.
+     </entry>
+     </row>
+
+     <row>
       <entry><structname>pg_stat_database</><indexterm><primary>pg_stat_database</primary></indexterm></entry>
       <entry>One row per database, showing database-wide statistics. See
        <xref linkend="pg-stat-database-view"> for details.
@@ -735,6 +743,39 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    single row, containing global data for the cluster.
   </para>
 
+  <table id="pg-stat-walwriter-view" xreflabel="pg_stat_walwriter">
+   <title><structname>pg_stat_walwriter</structname> View</title>
+
+   <tgroup cols="3">
+    <thead>
+    <row>
+      <entry>Column</entry>
+      <entry>Type</entry>
+      <entry>Description</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry><structfield>dirty_writes</></entry>
+      <entry><type>bigint</type></entry>
+      <entry>Number of dirty writes, which means flushing wal buffers
+       because of its full.</entry>
+     </row>
+     <row>
+      <entry><structfield>stats_reset</></entry>
+      <entry><type>timestamp with time zone</type></entry>
+      <entry>Time at which these statistics were last reset</entry>
+     </row>
+    </tbody>
+    </tgroup>
+  </table>
+
+  <para>
+   The <structname>pg_stat_walwriter</structname> view will always have a
+   single row, containing global data for the cluster.
+  </para>
+
   <table id="pg-stat-database-view" xreflabel="pg_stat_database">
    <title><structname>pg_stat_database</structname> View</title>
    <tgroup cols="3">
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index dc47c47..d0e85c9 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2467,6 +2467,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, bool opportunistic)
 					WriteRqst.Write = OldPageRqstPtr;
 					WriteRqst.Flush = 0;
 					XLogWrite(WriteRqst, false);
+					WalWriterStats.m_xlog_dirty_writes++;
 					LWLockRelease(WALWriteLock);
 					TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
 				}
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 575a40f..12a2ed0 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -686,6 +686,11 @@ CREATE VIEW pg_stat_bgwriter AS
         pg_stat_get_buf_alloc() AS buffers_alloc,
         pg_stat_get_bgwriter_stat_reset_time() AS stats_reset;
 
+CREATE VIEW pg_stat_walwriter AS
+    SELECT
+        pg_stat_get_xlog_dirty_writes() AS dirty_writes,
+        pg_stat_get_wal_stat_reset_time() AS stats_reset;
+
 CREATE VIEW pg_user_mappings AS
     SELECT
         U.oid       AS umid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index b5ce2f6..8c56af5 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -129,6 +129,14 @@ char	   *pgstat_stat_tmpname = NULL;
  */
 PgStat_MsgBgWriter BgWriterStats;
 
+/*
+ * WalWriter statistics counter.
+ * This counter is incremented by each XLogWrite call,
+ * both in the wal writer process and each backend.
+ * And then, sent to the stat collector process.
+ */
+PgStat_MsgWalWriter WalWriterStats;
+
 /* ----------
  * Local data
  * ----------
@@ -293,6 +301,7 @@ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len);
 static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len);
 static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len);
 static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
+static void pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
@@ -820,6 +829,9 @@ pgstat_report_stat(bool force)
 
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
+
+	/* Now, send wal buffer flush statistics */
+	pgstat_send_walwriter();
 }
 
 /*
@@ -1249,11 +1261,13 @@ pgstat_reset_shared_counters(const char *target)
 
 	if (strcmp(target, "bgwriter") == 0)
 		msg.m_resettarget = RESET_BGWRITER;
+	else if (strcmp(target, "walwriter") == 0)
+		msg.m_resettarget = RESET_WALWRITER;
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("unrecognized reset target: \"%s\"", target),
-				 errhint("Target must be \"bgwriter\".")));
+				 errhint("Target must be \"bgwriter\" or \"walwriter\".")));
 
 	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER);
 	pgstat_send(&msg, sizeof(msg));
@@ -3055,6 +3069,38 @@ pgstat_send_bgwriter(void)
 	MemSet(&BgWriterStats, 0, sizeof(BgWriterStats));
 }
 
+/* ----------
+ * pgstat_send_walwriter() -
+ *
+ *		Send walwriter statistics to the collector
+ * ----------
+ */
+void
+pgstat_send_walwriter(void)
+{
+	/* We assume this initializes to zeroes */
+	static const PgStat_MsgBgWriter all_zeroes;
+
+	/*
+	 * This function can be called even if nothing at all has happened. In
+	 * this case, avoid sending a completely empty message to the stats
+	 * collector.
+	 */
+	if (memcmp(&WalWriterStats, &all_zeroes, sizeof(PgStat_MsgWalWriter)) == 0)
+		return;
+
+	/*
+	 * Prepare and send the message
+	 */
+	pgstat_setheader(&WalWriterStats.m_hdr, PGSTAT_MTYPE_WALWRITER);
+	pgstat_send(&WalWriterStats, sizeof(WalWriterStats));
+
+	/*
+	 * Clear out the statistics buffer, so it can be re-used.
+	 */
+	MemSet(&WalWriterStats, 0, sizeof(WalWriterStats));
+}
+
 
 /* ----------
  * PgstatCollectorMain() -
@@ -3270,6 +3316,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_WALWRITER:
+					pgstat_recv_walwriter((PgStat_MsgWalWriter *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_FUNCSTAT:
 					pgstat_recv_funcstat((PgStat_MsgFuncstat *) &msg, len);
 					break;
@@ -3825,7 +3875,8 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 	 * Set the current timestamp (will be kept only in case we can't load an
 	 * existing statsfile).
 	 */
-	globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.bgWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	globalStats.walWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
 
 	/*
 	 * Try to open the stats file. If it doesn't exist, the backends simply
@@ -4723,8 +4774,23 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len)
 	if (msg->m_resettarget == RESET_BGWRITER)
 	{
 		/* Reset the global background writer statistics for the cluster. */
-		memset(&globalStats, 0, sizeof(globalStats));
-		globalStats.stat_reset_timestamp = GetCurrentTimestamp();
+		globalStats.bgWriterGlobalStats.timed_checkpoints       = 0;
+		globalStats.bgWriterGlobalStats.requested_checkpoints   = 0;
+		globalStats.bgWriterGlobalStats.checkpoint_write_time   = 0;
+		globalStats.bgWriterGlobalStats.checkpoint_sync_time    = 0;
+		globalStats.bgWriterGlobalStats.buf_written_checkpoints = 0;
+		globalStats.bgWriterGlobalStats.buf_written_clean       = 0;
+		globalStats.bgWriterGlobalStats.maxwritten_clean        = 0;
+		globalStats.bgWriterGlobalStats.buf_written_backend     = 0;
+		globalStats.bgWriterGlobalStats.buf_fsync_backend       = 0;
+		globalStats.bgWriterGlobalStats.buf_alloc               = 0;
+		globalStats.bgWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
+	}
+	else if (msg->m_resettarget == RESET_WALWRITER)
+	{
+		/* Reset the global walwriter statistics for the cluster. */
+		globalStats.walWriterGlobalStats.xlog_dirty_writes = 0;
+		globalStats.walWriterGlobalStats.stat_reset_timestamp = GetCurrentTimestamp();
 	}
 
 	/*
@@ -4865,16 +4931,28 @@ pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len)
 static void
 pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len)
 {
-	globalStats.timed_checkpoints += msg->m_timed_checkpoints;
-	globalStats.requested_checkpoints += msg->m_requested_checkpoints;
-	globalStats.checkpoint_write_time += msg->m_checkpoint_write_time;
-	globalStats.checkpoint_sync_time += msg->m_checkpoint_sync_time;
-	globalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
-	globalStats.buf_written_clean += msg->m_buf_written_clean;
-	globalStats.maxwritten_clean += msg->m_maxwritten_clean;
-	globalStats.buf_written_backend += msg->m_buf_written_backend;
-	globalStats.buf_fsync_backend += msg->m_buf_fsync_backend;
-	globalStats.buf_alloc += msg->m_buf_alloc;
+	globalStats.bgWriterGlobalStats.timed_checkpoints += msg->m_timed_checkpoints;
+	globalStats.bgWriterGlobalStats.requested_checkpoints += msg->m_requested_checkpoints;
+	globalStats.bgWriterGlobalStats.checkpoint_write_time += msg->m_checkpoint_write_time;
+	globalStats.bgWriterGlobalStats.checkpoint_sync_time += msg->m_checkpoint_sync_time;
+	globalStats.bgWriterGlobalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints;
+	globalStats.bgWriterGlobalStats.buf_written_clean += msg->m_buf_written_clean;
+	globalStats.bgWriterGlobalStats.maxwritten_clean += msg->m_maxwritten_clean;
+	globalStats.bgWriterGlobalStats.buf_written_backend += msg->m_buf_written_backend;
+	globalStats.bgWriterGlobalStats.buf_fsync_backend += msg->m_buf_fsync_backend;
+	globalStats.bgWriterGlobalStats.buf_alloc += msg->m_buf_alloc;
+}
+
+/* ----------
+ * pgstat_recv_walwriter() -
+ *
+ *	Process a WALWRITER message.
+ * ----------
+ */
+static void
+pgstat_recv_walwriter(PgStat_MsgWalWriter *msg, int len)
+{
+	globalStats.walWriterGlobalStats.xlog_dirty_writes += msg->m_xlog_dirty_writes;
 }
 
 /* ----------
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 8359da6..a6cdee2 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -49,6 +49,7 @@
 #include "access/xlog.h"
 #include "libpq/pqsignal.h"
 #include "miscadmin.h"
+#include "pgstat.h"
 #include "postmaster/walwriter.h"
 #include "storage/bufmgr.h"
 #include "storage/fd.h"
@@ -290,6 +291,8 @@ WalWriterMain(void)
 		else if (left_till_hibernate > 0)
 			left_till_hibernate--;
 
+		pgstat_send_walwriter();
+
 		/*
 		 * Sleep until we are signaled or WalWriterDelay has elapsed.  If we
 		 * haven't done anything useful for quite some time, lengthen the
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 0533cd6..df9f1d8 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -98,6 +98,7 @@ extern Datum pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_buf_alloc(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS);
 
 extern Datum pg_stat_get_xact_numscans(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_xact_tuples_returned(PG_FUNCTION_ARGS);
@@ -119,6 +120,8 @@ extern Datum pg_stat_reset_shared(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS);
 extern Datum pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS);
 
+extern Datum pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS);
+
 /* Global bgwriter statistics, from bgwriter.c */
 extern PgStat_MsgBgWriter bgwriterStats;
 
@@ -1409,69 +1412,75 @@ pg_stat_get_db_blk_write_time(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->timed_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.timed_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_requested_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->requested_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.requested_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_buf_written_checkpoints(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_checkpoints);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_checkpoints);
 }
 
 Datum
 pg_stat_get_bgwriter_buf_written_clean(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_clean);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_clean);
 }
 
 Datum
 pg_stat_get_bgwriter_maxwritten_clean(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->maxwritten_clean);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.maxwritten_clean);
 }
 
 Datum
 pg_stat_get_checkpoint_write_time(PG_FUNCTION_ARGS)
 {
 	/* time is already in msec, just convert to double for presentation */
-	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->checkpoint_write_time);
+	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->bgWriterGlobalStats.checkpoint_write_time);
 }
 
 Datum
 pg_stat_get_checkpoint_sync_time(PG_FUNCTION_ARGS)
 {
 	/* time is already in msec, just convert to double for presentation */
-	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->checkpoint_sync_time);
+	PG_RETURN_FLOAT8((double) pgstat_fetch_global()->bgWriterGlobalStats.checkpoint_sync_time);
 }
 
 Datum
 pg_stat_get_bgwriter_stat_reset_time(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stat_reset_timestamp);
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->bgWriterGlobalStats.stat_reset_timestamp);
 }
 
 Datum
 pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_written_backend);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_written_backend);
 }
 
 Datum
 pg_stat_get_buf_fsync_backend(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_fsync_backend);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_fsync_backend);
 }
 
 Datum
 pg_stat_get_buf_alloc(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_INT64(pgstat_fetch_global()->buf_alloc);
+	PG_RETURN_INT64(pgstat_fetch_global()->bgWriterGlobalStats.buf_alloc);
+}
+
+Datum
+pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->walWriterGlobalStats.stat_reset_timestamp);
 }
 
 Datum
@@ -1711,3 +1720,9 @@ pg_stat_reset_single_function_counters(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+Datum
+pg_stat_get_xlog_dirty_writes(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT64(pgstat_fetch_global()->walWriterGlobalStats.xlog_dirty_writes);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index f03dd0b..b1f9c54 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2709,6 +2709,8 @@ DATA(insert OID = 3063 ( pg_stat_get_buf_fsync_backend PGNSP PGUID 12 1 0 0 0 f
 DESCR("statistics: number of backend buffer writes that did their own fsync");
 DATA(insert OID = 2859 ( pg_stat_get_buf_alloc			PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_alloc _null_ _null_ _null_ ));
 DESCR("statistics: number of buffer allocations");
+DATA(insert OID = 3178 ( pg_stat_get_wal_stat_reset_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_	pg_stat_get_wal_stat_reset_time _null_ _null_ _null_ ));
+DESCR("statistics: last reset for the wal");
 
 DATA(insert OID = 2978 (  pg_stat_get_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls");
@@ -2753,6 +2755,9 @@ DESCR("statistics: reset collected statistics for a single table or index in the
 DATA(insert OID = 3777 (  pg_stat_reset_single_function_counters	PGNSP PGUID 12 1 0 0 0 f f f f f f v 1 0 2278 "26" _null_ _null_ _null_ _null_	pg_stat_reset_single_function_counters _null_ _null_ _null_ ));
 DESCR("statistics: reset collected statistics for a single function in the current database");
 
+DATA(insert OID = 3179 (  pg_stat_get_xlog_dirty_writes  PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_xlog_dirty_writes _null_ _null_ _null_ ));
+DESCR("statistics: get xlog dirty buffer write statistics");
+
 DATA(insert OID = 3163 (  pg_trigger_depth				PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 23 "" _null_ _null_ _null_ _null_ pg_trigger_depth _null_ _null_ _null_ ));
 DESCR("current trigger depth");
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fb242e4..1213964 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -45,6 +45,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_VACUUM,
 	PGSTAT_MTYPE_ANALYZE,
 	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WALWRITER,
 	PGSTAT_MTYPE_FUNCSTAT,
 	PGSTAT_MTYPE_FUNCPURGE,
 	PGSTAT_MTYPE_RECOVERYCONFLICT,
@@ -102,7 +103,8 @@ typedef struct PgStat_TableCounts
 /* Possible targets for resetting cluster-wide shared values */
 typedef enum PgStat_Shared_Reset_Target
 {
-	RESET_BGWRITER
+	RESET_BGWRITER,
+	RESET_WALWRITER
 } PgStat_Shared_Reset_Target;
 
 /* Possible object types for resetting single counters */
@@ -373,6 +375,17 @@ typedef struct PgStat_MsgBgWriter
 } PgStat_MsgBgWriter;
 
 /* ----------
+ * PgStat_MsgWalWriter			Sent by the walwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWalWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_xlog_dirty_writes;
+} PgStat_MsgWalWriter;
+
+/* ----------
  * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
  * ----------
  */
@@ -500,6 +513,7 @@ typedef union PgStat_Msg
 	PgStat_MsgVacuum msg_vacuum;
 	PgStat_MsgAnalyze msg_analyze;
 	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWalWriter msg_walwriter;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
@@ -608,12 +622,8 @@ typedef struct PgStat_StatFuncEntry
 } PgStat_StatFuncEntry;
 
 
-/*
- * Global statistics kept in the stats collector
- */
-typedef struct PgStat_GlobalStats
+typedef struct PgStat_BgWriterGlobalStats
 {
-	TimestampTz stats_timestamp;	/* time of stats file update */
 	PgStat_Counter timed_checkpoints;
 	PgStat_Counter requested_checkpoints;
 	PgStat_Counter checkpoint_write_time;		/* times in milliseconds */
@@ -625,6 +635,22 @@ typedef struct PgStat_GlobalStats
 	PgStat_Counter buf_fsync_backend;
 	PgStat_Counter buf_alloc;
 	TimestampTz stat_reset_timestamp;
+} PgStat_BgWriterGlobalStats;
+
+typedef struct PgStat_WalWriterGlobalStats
+{
+	PgStat_Counter xlog_dirty_writes;
+	TimestampTz stat_reset_timestamp;
+} PgStat_WalWriterGlobalStats;
+
+/*
+ * Global statistics kept in the stats collector
+ */
+typedef struct PgStat_GlobalStats
+{
+	TimestampTz stats_timestamp;    /* time of stats file update */
+	PgStat_BgWriterGlobalStats bgWriterGlobalStats;
+	PgStat_WalWriterGlobalStats walWriterGlobalStats;
 } PgStat_GlobalStats;
 
 
@@ -733,6 +759,8 @@ extern char *pgstat_stat_filename;
  */
 extern PgStat_MsgBgWriter BgWriterStats;
 
+extern PgStat_MsgWalWriter WalWriterStats;
+
 /*
  * Updated by pgstat_count_buffer_*_time macros
  */
@@ -861,6 +889,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
 						  void *recdata, uint32 len);
 
 extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_walwriter(void);
 
 /* ----------
  * Support functions for the SQL-callable functions to
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 8f24c51..4074c61 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1775,6 +1775,8 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
                                  |     pg_stat_all_tables.autoanalyze_count                                                                                                                                                                       +
                                  |    FROM pg_stat_all_tables                                                                                                                                                                                     +
                                  |   WHERE ((pg_stat_all_tables.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_tables.schemaname !~ '^pg_toast'::text));
+ pg_stat_walwriter               |  SELECT pg_stat_get_xlog_dirty_writes() AS dirty_writes,                                                                                                                                                       +
+                                 |     pg_stat_get_wal_stat_reset_time() AS stats_reset;
  pg_stat_xact_all_tables         |  SELECT c.oid AS relid,                                                                                                                                                                                        +
                                  |     n.nspname AS schemaname,                                                                                                                                                                                   +
                                  |     c.relname,                                                                                                                                                                                                 +
@@ -2142,7 +2144,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
                                  |    FROM tv;
  tvvmv                           |  SELECT tvvm.grandtot                                                                                                                                                                                          +
                                  |    FROM tvvm;
-(64 rows)
+(65 rows)
 
 SELECT tablename, rulename, definition FROM pg_rules
 	ORDER BY tablename, rulename;