Add support for tracking call counts and elapsed runtime for user-defined

functions.

Note that because this patch changes FmgrInfo, any external C functions
you might be testing with 8.4 will need to be recompiled.

Patch by Martin Pihlak, some editorialization by me (principally, removing
tracking of getrusage() numbers)

Author: tglsfdc

doc/src/sgml/config.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.177 2008/05/02 21:26:09 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.178 2008/05/15 00:17:39 tgl Exp $ -->
 
 <chapter Id="runtime-config">
   <title>Server Configuration</title>
@@ -3342,6 +3342,22 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-functions" xreflabel="track_functions">
+      <term><varname>track_functions</varname> (<type>string</type>)</term>
+      <indexterm>
+       <primary><varname>track_functions</> configuration parameter</primary>
+      </indexterm>
+      <listitem>
+       <para>
+        Enables tracking of function call counts and time used. Specify
+        <literal>pl</literal> to count only procedural language functions,
+        <literal>all</literal> to also track SQL and C language functions.
+        The default is <literal>none</literal>.
+        Only superusers can change this setting.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-update-process-title" xreflabel="update_process_title">
       <term><varname>update_process_title</varname> (<type>boolean</type>)</term>
       <indexterm>

doc/src/sgml/monitoring.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/monitoring.sgml,v 1.58 2008/05/07 14:41:55 mha Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/monitoring.sgml,v 1.59 2008/05/15 00:17:39 tgl Exp $ -->
 
 <chapter id="monitoring">
  <title>Monitoring Database Activity</title>
@@ -119,7 +119,8 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    server activity.  Presently, the collector can count accesses to tables
    and indexes in both disk-block and individual-row terms.  It also tracks
    total numbers of rows in each table, and the last vacuum and analyze times
-   for each table.
+   for each table.  It can also count calls to user-defined functions and
+   the total time spent in each one.
   </para>
 
   <para>
@@ -141,15 +142,19 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
 
   <para>
    The parameter <xref linkend="guc-track-counts"> controls whether
-   information is actually sent to the collector process and thus determines
-   whether any run-time overhead occurs for event counting.
+   statistics are collected about table and index accesses.
+  </para>
+
+  <para>
+   The parameter <xref linkend="guc-track-functions"> enables tracking of
+   usage of user-defined functions.
   </para>
 
   <para>
    The parameter <xref linkend="guc-track-activities"> enables monitoring
    of the current command being executed by any server process.
   </para>
-  
+
   <para>
    Normally these parameters are set in <filename>postgresql.conf</> so
    that they apply to all server processes, but it is possible to turn
@@ -370,6 +375,16 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
       <entry>Same as <structname>pg_statio_all_sequences</>, except that only
       user sequences are shown.</entry>
      </row>
+
+     <row>
+      <entry><structname>pg_stat_user_functions</></entry>
+      <entry>For all tracked functions, function OID, schema, name, number
+      of calls, total time, and self time.  Self time is the
+      amount of time spent in the function itself, total time includes the
+      time spent in functions it called. Time values are in milliseconds.
+     </entry>
+     </row>
+
     </tbody>
    </tgroup>
   </table>
@@ -429,8 +444,9 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
    linkend="monitoring-stats-funcs-table">.  The per-database access
    functions take a database OID as argument to identify which
    database to report on.  The per-table and per-index functions take
-   a table or index OID.  (Note that only tables and indexes in the
-   current database can be seen with these functions.)  The
+   a table or index OID.  The functions for function-call statistics
+   take a function OID.  (Note that only tables, indexes, and functions
+   in the current database can be seen with these functions.)  The
    per-server-process access functions take a server process
    number, which ranges from one to the number of currently active
    server processes.
@@ -674,6 +690,32 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re
       </entry>
      </row>
 
+     <row>
+      <entry><literal><function>pg_stat_get_function_calls</function>(<type>oid</type>)</literal></entry>
+      <entry><type>bigint</type></entry>
+      <entry>
+       Number of times the function has been called.
+      </entry>
+     </row>
+
+     <row>
+      <entry><literal><function>pg_stat_get_function_time</function>(<type>oid</type>)</literal></entry>
+      <entry><type>bigint</type></entry>
+      <entry>
+       Total wall clock time spent in the function, in microseconds.  Includes
+       the time spent in functions called by this one.
+      </entry>
+     </row>
+
+     <row>
+      <entry><literal><function>pg_stat_get_function_self_time</function>(<type>oid</type>)</literal></entry>
+      <entry><type>bigint</type></entry>
+      <entry>
+       Time spent in only this function. Time spent in called functions
+       is excluded.
+      </entry>
+     </row>
+
      <row>
       <entry><literal><function>pg_stat_get_backend_idset</function>()</literal></entry>
       <entry><type>setof integer</type></entry>

src/backend/catalog/system_views.sql

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 1996-2008, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.51 2008/05/08 08:58:59 mha Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.52 2008/05/15 00:17:39 tgl Exp $
  */
 
 CREATE VIEW pg_roles AS 
@@ -374,6 +374,18 @@ CREATE VIEW pg_stat_database AS
             pg_stat_get_db_tuples_deleted(D.oid) AS tup_deleted
     FROM pg_database D;
 
+CREATE VIEW pg_stat_user_functions AS 
+    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_time(P.oid) / 1000 AS total_time,
+            pg_stat_get_function_self_time(P.oid) / 1000 AS self_time
+    FROM pg_proc P LEFT JOIN pg_namespace N ON (N.oid = P.pronamespace)
+    WHERE P.prolang != 12  -- fast check to eliminate built-in functions   
+          AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
+
 CREATE VIEW pg_stat_bgwriter AS
     SELECT
         pg_stat_get_bgwriter_timed_checkpoints() AS checkpoints_timed,

src/backend/commands/trigger.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.233 2008/05/12 20:01:59 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.234 2008/05/15 00:17:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,6 +32,7 @@
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "parser/parse_func.h"
+#include "pgstat.h"
 #include "storage/bufmgr.h"
 #include "tcop/utility.h"
 #include "utils/acl.h"
@@ -1566,6 +1567,7 @@ ExecCallTriggerFunc(TriggerData *trigdata,
 					MemoryContext per_tuple_context)
 {
 	FunctionCallInfoData fcinfo;
+	PgStat_FunctionCallUsage fcusage;
 	Datum		result;
 	MemoryContext oldContext;
 
@@ -1599,8 +1601,12 @@ ExecCallTriggerFunc(TriggerData *trigdata,
 	 */
 	InitFunctionCallInfoData(fcinfo, finfo, 0, (Node *) trigdata, NULL);
 
+	pgstat_init_function_usage(&fcinfo, &fcusage);
+
 	result = FunctionCallInvoke(&fcinfo);
 
+	pgstat_end_function_usage(&fcusage, true);
+
 	MemoryContextSwitchTo(oldContext);
 
 	/*

src/backend/commands/vacuum.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.373 2008/05/12 20:02:00 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.374 2008/05/15 00:17:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -323,7 +323,7 @@ vacuum(VacuumStmt *vacstmt, List *relids,
 	 * in autovacuum --- autovacuum.c does this for itself.
 	 */
 	if (vacstmt->vacuum && !IsAutoVacuumWorkerProcess())
-		pgstat_vacuum_tabstat();
+		pgstat_vacuum_stat();
 
 	/*
 	 * Create special memory context for cross-transaction storage.

src/backend/executor/execQual.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.230 2008/05/12 00:00:48 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.231 2008/05/15 00:17:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,6 +46,7 @@
 #include "nodes/makefuncs.h"
 #include "optimizer/planmain.h"
 #include "parser/parse_expr.h"
+#include "pgstat.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
@@ -1147,6 +1148,7 @@ ExecMakeFunctionResult(FuncExprState *fcache,
 	List	   *arguments = fcache->args;
 	Datum		result;
 	FunctionCallInfoData fcinfo;
+	PgStat_FunctionCallUsage fcusage;
 	ReturnSetInfo rsinfo;		/* for functions returning sets */
 	ExprDoneCond argDone;
 	bool		hasSetArg;
@@ -1250,11 +1252,16 @@ ExecMakeFunctionResult(FuncExprState *fcache,
 
 			if (callit)
 			{
+				pgstat_init_function_usage(&fcinfo, &fcusage);
+
 				fcinfo.isnull = false;
 				rsinfo.isDone = ExprSingleResult;
 				result = FunctionCallInvoke(&fcinfo);
 				*isNull = fcinfo.isnull;
 				*isDone = rsinfo.isDone;
+
+				pgstat_end_function_usage(&fcusage,
+										  rsinfo.isDone != ExprMultipleResult);
 			}
 			else
 			{
@@ -1346,9 +1353,14 @@ ExecMakeFunctionResult(FuncExprState *fcache,
 				}
 			}
 		}
+
+		pgstat_init_function_usage(&fcinfo, &fcusage);
+
 		fcinfo.isnull = false;
 		result = FunctionCallInvoke(&fcinfo);
 		*isNull = fcinfo.isnull;
+
+		pgstat_end_function_usage(&fcusage, true);
 	}
 
 	return result;
@@ -1369,6 +1381,7 @@ ExecMakeFunctionResultNoSets(FuncExprState *fcache,
 	ListCell   *arg;
 	Datum		result;
 	FunctionCallInfoData fcinfo;
+	PgStat_FunctionCallUsage fcusage;
 	int			i;
 
 	/* Guard against stack overflow due to overly complex expressions */
@@ -1407,10 +1420,15 @@ ExecMakeFunctionResultNoSets(FuncExprState *fcache,
 			}
 		}
 	}
+
+	pgstat_init_function_usage(&fcinfo, &fcusage);
+
 	/* fcinfo.isnull = false; */	/* handled by InitFunctionCallInfoData */
 	result = FunctionCallInvoke(&fcinfo);
 	*isNull = fcinfo.isnull;
 
+	pgstat_end_function_usage(&fcusage, true);
+
 	return result;
 }
 
@@ -1434,6 +1452,7 @@ ExecMakeTableFunctionResult(ExprState *funcexpr,
 	bool		returnsTuple;
 	bool		returnsSet = false;
 	FunctionCallInfoData fcinfo;
+	PgStat_FunctionCallUsage fcusage;
 	ReturnSetInfo rsinfo;
 	HeapTupleData tmptup;
 	MemoryContext callerContext;
@@ -1559,9 +1578,14 @@ ExecMakeTableFunctionResult(ExprState *funcexpr,
 		/* Call the function or expression one time */
 		if (direct_function_call)
 		{
+			pgstat_init_function_usage(&fcinfo, &fcusage);
+
 			fcinfo.isnull = false;
 			rsinfo.isDone = ExprSingleResult;
 			result = FunctionCallInvoke(&fcinfo);
+
+			pgstat_end_function_usage(&fcusage,
+									  rsinfo.isDone != ExprMultipleResult);
 		}
 		else
 		{

src/backend/postmaster/autovacuum.c

@@ -55,7 +55,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.77 2008/05/12 00:00:50 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.78 2008/05/15 00:17:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1857,7 +1857,7 @@ do_autovacuum(void)
 	 * want to do this exactly once per DB-processing cycle, even if we find
 	 * nothing worth vacuuming in the database.
 	 */
-	pgstat_vacuum_tabstat();
+	pgstat_vacuum_stat();
 
 	/*
 	 * Find the pg_database entry and select the default freeze_min_age. We