Complete the following TODO items:

* Add session start time to pg_stat_activity
* Add the client IP address and port to pg_stat_activity

Original patch from Magnus Hagander, code review by Neil Conway. Catalog
version bumped. This patch sends the client IP address and port number in
every statistics message; that's not ideal, but will be fixed up shortly.

doc/src/sgml/monitoring.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/monitoring.sgml,v 1.27 2004/12/28 19:08:58 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/monitoring.sgml,v 1.28 2005/05/09 11:31:32 neilc Exp $
 -->
 
 <chapter id="monitoring">
@@ -221,15 +221,16 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
      <row>
       <entry><structname>pg_stat_activity</></entry>
       <entry>One row per server process, showing process
-      <acronym>ID</>, database, user, current query, and the time at
-      which the current query began execution. The columns that report
-      data on the current query are only available if the parameter
-      <varname>stats_command_string</varname> has been turned on.
-      Furthermore, these columns read as null unless the user examining
-      the view is a superuser or the same as the user owning the process
-      being reported on.  (Note that because of the 
-      collector's reporting delay, current query will only be up-to-date for 
-      long-running queries.)</entry>
+      <acronym>ID</>, database, user, current query, the time at which
+      the current query began execution, the time at which the backend
+      was started and the client address and port number.  The columns
+      that report data on the current query are only available if the
+      parameter <varname>stats_command_string</varname> has been
+      turned on.  Furthermore, these columns read as null unless the
+      user examining the view is a superuser or the same as the user
+      owning the process being reported on.  (Note that because of the
+      collector's reporting delay, the current query will only be
+      up-to-date for long-running queries.)</entry>
      </row>
 
      <row>
@@ -509,7 +510,7 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
       <entry><type>set of integer</type></entry>
       <entry>
        Set of currently active backend process IDs (from 1 to the
-       number of active backend processes).  See usage example in the text.
+       number of active backend processes).  See usage example in the text
       </entry>
      </row>
 
@@ -568,6 +569,38 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
       </entry>
      </row>
 
+     <row>
+      <entry><literal><function>pg_stat_get_backend_start</function>(<type>integer</type>)</literal></entry>
+      <entry><type>timestamp with time zone</type></entry>
+      <entry>
+       The time at which the given backend process was started, or
+       null if the current user is not a superuser nor the same user
+       as that of the session being queried
+      </entry>
+     </row>
+
+     <row>
+      <entry><literal><function>pg_stat_get_backend_client_addr</function>(<type>integer</type>)</literal></entry>
+      <entry><type>inet</type></entry>
+      <entry>
+       The IP address of the client connected to the given
+       backend. Null if the connection is over a Unix domain
+       socket. Also null if the current user is not a superuser nor
+       the same user as that of the session being queried
+      </entry>
+     </row>
+
+     <row>
+      <entry><literal><function>pg_stat_get_backend_client_port</function>(<type>integer</type>)</literal></entry>
+      <entry><type>integer</type></entry>
+      <entry>
+       The IP port number of the client connected to the given
+       backend.  -1 if the connection is over a Unix domain
+       socket. Null if the current user is not a superuser nor the
+       same user as that of the session being queried
+      </entry>
+     </row>
+
      <row>
       <entry><literal><function>pg_stat_reset</function>()</literal></entry>
       <entry><type>boolean</type></entry>

src/backend/catalog/system_views.sql

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 1996-2005, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.11 2005/01/01 20:44:14 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.12 2005/05/09 11:31:32 neilc Exp $
  */
 
 CREATE VIEW pg_user AS 
@@ -237,7 +237,10 @@ CREATE VIEW pg_stat_activity AS
             pg_stat_get_backend_userid(S.backendid) AS usesysid, 
             U.usename AS usename, 
             pg_stat_get_backend_activity(S.backendid) AS current_query, 
-            pg_stat_get_backend_activity_start(S.backendid) AS query_start 
+            pg_stat_get_backend_activity_start(S.backendid) AS query_start,
+            pg_stat_get_backend_start(S.backendid) AS backend_start,
+            pg_stat_get_backend_client_addr(S.backendid) AS client_addr,
+            pg_stat_get_backend_client_port(S.backendid) AS client_port
     FROM pg_database D, 
             (SELECT pg_stat_get_backend_idset() AS backendid) AS S, 
             pg_shadow U 

src/backend/postmaster/pgstat.c

@@ -13,7 +13,7 @@
  *
  *	Copyright (c) 2001-2005, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.92 2005/04/14 20:32:42 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.93 2005/05/09 11:31:33 neilc Exp $
  * ----------
  */
 #include "postgres.h"
@@ -1300,6 +1300,7 @@ pgstat_setheader(PgStat_MsgHdr *hdr, int mtype)
 	hdr->m_procpid = MyProcPid;
 	hdr->m_databaseid = MyDatabaseId;
 	hdr->m_userid = GetSessionUserId();
+	memcpy(&hdr->m_clientaddr, &MyProcPort->raddr, sizeof(hdr->m_clientaddr));
 }
 
 
@@ -2032,12 +2033,15 @@ pgstat_add_backend(PgStat_MsgHdr *msg)
 	beentry->databaseid = msg->m_databaseid;
 	beentry->procpid = msg->m_procpid;
 	beentry->userid = msg->m_userid;
+	beentry->start_sec = 
+		GetCurrentAbsoluteTimeUsec(&beentry->start_usec);
 	beentry->activity_start_sec = 0;
 	beentry->activity_start_usec = 0;
+	memcpy(&beentry->clientaddr, &msg->m_clientaddr, sizeof(beentry->clientaddr));
 	MemSet(beentry->activity, 0, PGSTAT_ACTIVITY_SIZE);
 
 	/*
-	 * Lookup or create the database entry for this backends DB.
+	 * Lookup or create the database entry for this backend's DB.
 	 */
 	dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
 										   (void *) &(msg->m_databaseid),
@@ -2072,9 +2076,7 @@ pgstat_add_backend(PgStat_MsgHdr *msg)
 									  HASH_ELEM | HASH_FUNCTION);
 	}
 
-	/*
-	 * Count number of connects to the database
-	 */
+	/* Count the number of connects to the database */
 	dbentry->n_connects++;
 
 	return 0;

src/backend/utils/adt/pgstatfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/pgstatfuncs.c,v 1.20 2004/12/31 22:01:22 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/pgstatfuncs.c,v 1.21 2005/05/09 11:31:33 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,6 +22,9 @@
 #include "nodes/execnodes.h"
 #include "pgstat.h"
 #include "utils/hsearch.h"
+#include "utils/inet.h"
+#include "utils/builtins.h"
+#include "libpq/ip.h"
 
 /* bogus ... these externs should be in a header file */
 extern Datum pg_stat_get_numscans(PG_FUNCTION_ARGS);
@@ -41,6 +44,9 @@ extern Datum pg_stat_get_backend_dbid(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_backend_userid(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_backend_activity(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_backend_activity_start(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_start(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_client_addr(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_backend_client_port(PG_FUNCTION_ARGS);
 
 extern Datum pg_stat_get_db_numbackends(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_xact_commit(PG_FUNCTION_ARGS);
@@ -357,6 +363,117 @@ pg_stat_get_backend_activity_start(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMPTZ(result);
 }
 
+Datum
+pg_stat_get_backend_start(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry *beentry;
+	int32       beid;
+	AbsoluteTime sec;
+	int         usec;
+	TimestampTz result;
+
+	beid = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	if (!superuser() && beentry->userid != GetUserId())
+		PG_RETURN_NULL();
+
+	sec = beentry->start_sec;
+	usec = beentry->start_usec;
+
+	if (sec == 0 && usec == 0)
+		PG_RETURN_NULL();
+
+	result = AbsoluteTimeUsecToTimestampTz(sec, usec);
+
+	PG_RETURN_TIMESTAMPTZ(result);
+}
+
+
+Datum
+pg_stat_get_backend_client_addr(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry *beentry;
+	int32       beid;
+	char		remote_host[NI_MAXHOST];
+	int			ret;
+
+	beid = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	if (!superuser() && beentry->userid != GetUserId())
+		PG_RETURN_NULL();
+
+	switch (beentry->clientaddr.addr.ss_family)
+	{
+		case AF_INET:
+#ifdef HAVE_IPV6
+		case AF_INET6:
+#endif
+			break;
+		default:
+			PG_RETURN_NULL();
+	}
+
+	remote_host[0] = '\0';
+
+	ret = getnameinfo_all(&beentry->clientaddr.addr, beentry->clientaddr.salen,
+						  remote_host, sizeof(remote_host),
+						  NULL, 0,
+						  NI_NUMERICHOST | NI_NUMERICSERV);
+	if (ret)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INET_P(DirectFunctionCall1(inet_in,
+										 CStringGetDatum(remote_host)));
+}
+
+Datum
+pg_stat_get_backend_client_port(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry *beentry;
+	int32       beid;
+	char		remote_port[NI_MAXSERV];
+	int			ret;
+
+	beid = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	if (!superuser() && beentry->userid != GetUserId())
+		PG_RETURN_NULL();
+
+	switch (beentry->clientaddr.addr.ss_family)
+	{
+		case AF_INET:
+#ifdef HAVE_IPV6
+		case AF_INET6:
+#endif
+			break;
+		case AF_UNIX:
+			PG_RETURN_INT32(-1);
+		default:
+			PG_RETURN_NULL();
+	}
+
+	remote_port[0] = '\0';
+
+	ret = getnameinfo_all(&beentry->clientaddr.addr,
+						  beentry->clientaddr.salen,
+						  NULL, 0,
+						  remote_port, sizeof(remote_port),
+						  NI_NUMERICHOST | NI_NUMERICSERV);
+	if (ret)
+		PG_RETURN_NULL();
+
+	PG_RETURN_DATUM(DirectFunctionCall1(int4in, CStringGetDatum(remote_port)));
+}
+
 
 Datum
 pg_stat_get_db_numbackends(PG_FUNCTION_ARGS)

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.266 2005/04/30 20:31:37 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.267 2005/05/09 11:31:34 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200504301
+#define CATALOG_VERSION_NO	200505091
 
 #endif

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.360 2005/04/30 20:31:38 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.361 2005/05/09 11:31:34 neilc Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -2822,6 +2822,12 @@ DATA(insert OID = 1940 (  pg_stat_get_backend_activity	PGNSP PGUID 12 f f t f s
 DESCR("Statistics: Current query of backend");
 DATA(insert OID = 2094 (  pg_stat_get_backend_activity_start PGNSP PGUID 12 f f t f s 1 1184 "23" _null_ _null_ _null_  pg_stat_get_backend_activity_start - _null_));
 DESCR("Statistics: Start time for current query of backend");
+DATA(insert OID = 1391 ( pg_stat_get_backend_start PGNSP PGUID 12 f f t f s 1 1184 "23" _null_ _null_ _null_ pg_stat_get_backend_start - _null_));
+DESCR("Statistics: Start time for current backend session");
+DATA(insert OID = 1392 ( pg_stat_get_backend_client_addr PGNSP PGUID 12 f f t f s 1 869 "23" _null_ _null_ _null_ pg_stat_get_backend_client_addr - _null_));
+DESCR("Statistics: Address of client connected to backend");
+DATA(insert OID = 1393 ( pg_stat_get_backend_client_port PGNSP PGUID 12 f f t f s 1 23 "23" _null_ _null_ _null_ pg_stat_get_backend_client_port - _null_));
+DESCR("Statistics: Port number of client connected to backend");
 DATA(insert OID = 1941 (  pg_stat_get_db_numbackends	PGNSP PGUID 12 f f t f s 1 23 "26" _null_ _null_ _null_	pg_stat_get_db_numbackends - _null_ ));
 DESCR("Statistics: Number of backends in database");
 DATA(insert OID = 1942 (  pg_stat_get_db_xact_commit	PGNSP PGUID 12 f f t f s 1 20 "26" _null_ _null_ _null_	pg_stat_get_db_xact_commit - _null_ ));

src/include/pgstat.h

@@ -5,17 +5,17 @@
  *
  *	Copyright (c) 2001-2005, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/include/pgstat.h,v 1.27 2005/01/01 05:43:08 momjian Exp $
+ *	$PostgreSQL: pgsql/src/include/pgstat.h,v 1.28 2005/05/09 11:31:33 neilc Exp $
  * ----------
  */
 #ifndef PGSTAT_H
 #define PGSTAT_H
 
+#include "libpq/pqcomm.h"
 #include "utils/hsearch.h"
 #include "utils/nabstime.h"
 #include "utils/rel.h"
 
-
 /* ----------
  * The types of backend/postmaster -> collector messages
  * ----------
@@ -54,6 +54,7 @@ typedef struct PgStat_MsgHdr
 	int			m_procpid;
 	Oid			m_databaseid;
 	AclId		m_userid;
+	SockAddr	m_clientaddr;
 } PgStat_MsgHdr;
 
 /* ----------
@@ -231,8 +232,11 @@ typedef struct PgStat_StatBeEntry
 	Oid			databaseid;
 	Oid			userid;
 	int			procpid;
+	AbsoluteTime start_sec;
+	int         start_usec;
 	AbsoluteTime activity_start_sec;
 	int			activity_start_usec;
+	SockAddr    clientaddr;
 	char		activity[PGSTAT_ACTIVITY_SIZE];
 } PgStat_StatBeEntry;