Re: getpid() function - Mailing list pgsql-hackers

OK, renamed to backend_pid() to match the libpq name.  I was unsure
about merging it into the stats stuff myself.

    setest=> select backend_pid();
     backend_pid
    -------------
           12996
    (1 row)

Where does the mention belong in the docs? I have it in the monitoring
section in the stats section right now.

---------------------------------------------------------------------------

Neil Conway wrote:
> On Tue, Jul 30, 2002 at 08:40:13PM -0400, Bruce Momjian wrote:
> > I have implemented this TODO item:
> >
> >     * Add getpid() function to backend
> >
> > There were a large number of pg_stat functions that access pids and
> > backends slots so I added it there:
> >
> >     test=> select pg_stat_get_backend_mypid();
>
> If we're going to add it to pg_stat_*, why is 'backend' part of the
> name? All the existing backend_* function fetch some piece of data
> about a given backend -- whereas this function does not (it takes
> no arguments).
>
> IMHO, a better name would be something like 'backend_process_id()',
> or 'unix_pid', or 'backend_pid()'.
>
> Also, can you add some documentation on this?
>
> Cheers,
>
> Neil
>
> --
> Neil Conway <neilconway@rogers.com>
> PGP Key ID: DB3C29FC
>

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026
Index: doc/src/sgml/monitoring.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/monitoring.sgml,v
retrieving revision 1.7
diff -c -r1.7 monitoring.sgml
*** doc/src/sgml/monitoring.sgml    22 Mar 2002 19:20:14 -0000    1.7
--- doc/src/sgml/monitoring.sgml    31 Jul 2002 01:42:11 -0000
***************
*** 481,490 ****
       </row>

       <row>
        <entry><function>pg_stat_get_backend_pid</function>(<type>integer</type>)</entry>
        <entry><type>integer</type></entry>
        <entry>
!        PID of backend process
        </entry>
       </row>

--- 481,498 ----
       </row>

       <row>
+       <entry><function>backend_pid</function>()</entry>
+       <entry><type>integer</type></entry>
+       <entry>
+        Process ID of current backend
+       </entry>
+      </row>
+
+      <row>
        <entry><function>pg_stat_get_backend_pid</function>(<type>integer</type>)</entry>
        <entry><type>integer</type></entry>
        <entry>
!        Process ID of all backend processes
        </entry>
       </row>

Index: src/backend/utils/adt/pgstatfuncs.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/pgstatfuncs.c,v
retrieving revision 1.5
diff -c -r1.5 pgstatfuncs.c
*** src/backend/utils/adt/pgstatfuncs.c    31 Jul 2002 00:40:40 -0000    1.5
--- src/backend/utils/adt/pgstatfuncs.c    31 Jul 2002 01:42:12 -0000
***************
*** 19,25 ****
  extern Datum pg_stat_get_blocks_hit(PG_FUNCTION_ARGS);

  extern Datum pg_stat_get_backend_idset(PG_FUNCTION_ARGS);
! extern Datum pg_stat_get_backend_mypid(PG_FUNCTION_ARGS);
  extern Datum pg_stat_get_backend_pid(PG_FUNCTION_ARGS);
  extern Datum pg_stat_get_backend_dbid(PG_FUNCTION_ARGS);
  extern Datum pg_stat_get_backend_userid(PG_FUNCTION_ARGS);
--- 19,25 ----
  extern Datum pg_stat_get_blocks_hit(PG_FUNCTION_ARGS);

  extern Datum pg_stat_get_backend_idset(PG_FUNCTION_ARGS);
! extern Datum backend_pid(PG_FUNCTION_ARGS);
  extern Datum pg_stat_get_backend_pid(PG_FUNCTION_ARGS);
  extern Datum pg_stat_get_backend_dbid(PG_FUNCTION_ARGS);
  extern Datum pg_stat_get_backend_userid(PG_FUNCTION_ARGS);
***************
*** 213,219 ****


  Datum
! pg_stat_get_backend_mypid(PG_FUNCTION_ARGS)
  {
      PG_RETURN_INT32(MyProcPid);
  }
--- 213,219 ----


  Datum
! backend_pid(PG_FUNCTION_ARGS)
  {
      PG_RETURN_INT32(MyProcPid);
  }
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/catalog/pg_proc.h,v
retrieving revision 1.247
diff -c -r1.247 pg_proc.h
*** src/include/catalog/pg_proc.h    31 Jul 2002 00:40:40 -0000    1.247
--- src/include/catalog/pg_proc.h    31 Jul 2002 01:42:20 -0000
***************
*** 2703,2710 ****
  DESCR("Statistics: Number of blocks found in cache");
  DATA(insert OID = 1936 (  pg_stat_get_backend_idset        PGNSP PGUID 12 f f t t s 0 23 ""
pg_stat_get_backend_idset- _null_ )); 
  DESCR("Statistics: Currently active backend IDs");
! DATA(insert OID = 2026 (  pg_stat_get_backend_mypid        PGNSP PGUID 12 f f t f s 0 23 ""
pg_stat_get_backend_mypid- _null_ )); 
! DESCR("Statistics: My backend ID");
  DATA(insert OID = 1937 (  pg_stat_get_backend_pid        PGNSP PGUID 12 f f t f s 1 23 "23"  pg_stat_get_backend_pid
-_null_ )); 
  DESCR("Statistics: PID of backend");
  DATA(insert OID = 1938 (  pg_stat_get_backend_dbid        PGNSP PGUID 12 f f t f s 1 26 "23"
pg_stat_get_backend_dbid- _null_ )); 
--- 2703,2710 ----
  DESCR("Statistics: Number of blocks found in cache");
  DATA(insert OID = 1936 (  pg_stat_get_backend_idset        PGNSP PGUID 12 f f t t s 0 23 ""
pg_stat_get_backend_idset- _null_ )); 
  DESCR("Statistics: Currently active backend IDs");
! DATA(insert OID = 2026 (  backend_pid                    PGNSP PGUID 12 f f t f s 0 23 ""    backend_pid - _null_ ));
! DESCR("Statistics: Current backend ID");
  DATA(insert OID = 1937 (  pg_stat_get_backend_pid        PGNSP PGUID 12 f f t f s 1 23 "23"  pg_stat_get_backend_pid
-_null_ )); 
  DESCR("Statistics: PID of backend");
  DATA(insert OID = 1938 (  pg_stat_get_backend_dbid        PGNSP PGUID 12 f f t f s 1 26 "23"
pg_stat_get_backend_dbid- _null_ ));