Re: Order of pg_stat_activity timestamp columns - Mailing list pgsql-hackers

Tom Lane wrote:
> "Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> > Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >> The current column ordering can be rationalized to some extent as
> >>
> >> 1. identity info (user id, db id, application name)
> >> 2. current query info
> >> 3. session info (backend start time, client addr/port)
>
> > OK.  I guess that trumps my idea, although it would sure be nice if
> > it were possible to swap 2 and 3 so that we could put the query text
> > at the end.
>
> Well, the current ordering is definitely historical rather than
> designed, but I'm hesitant to do more than minor tweaking.  Even if we
> think/hope it won't break applications, people are probably used to
> seeing a particular ordering.
>
> I'm not necessarily dead set against it though.  I guess if we were
> to do what you suggest, we'd end up with
>
> identity:
>  datid            | oid                      |
>  datname          | name                     |
>  procpid          | integer                  |
>  usesysid         | oid                      |
>  usename          | name                     |
>  application_name | text                     |
> session:
>  client_addr      | inet                     |
>  client_port      | integer                  |
>  backend_start    | timestamp with time zone |
> transaction:
>  xact_start       | timestamp with time zone |
> query:
>  query_start      | timestamp with time zone |
>  waiting          | boolean                  |
>  current_query    | text                     |
>
> or possibly that plus relocate procpid somewhere else.  Anyone think
> this is sufficiently better to justify possible confusion?

I implemented Tom's suggested ordering above:

    test=> SELECT * FROM pg_stat_activity;
    -[ RECORD 1 ]----+--------------------------------
    datid            | 16384
    datname          | test
    procpid          | 22216
    usesysid         | 10
    usename          | postgres
    application_name | psql
    client_addr      |
    client_port      | -1
    backend_start    | 2010-04-24 22:35:21.683308-04
    xact_start       | 2010-04-24 22:47:19.53821-04
    query_start      | 2010-04-24 22:47:19.53821-04
    waiting          | f
    current_query    | SELECT * FROM pg_stat_activity;

Patch attached.  It will require a catversion bump too.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com
Index: src/backend/catalog/system_views.sql
===================================================================
RCS file: /cvsroot/pgsql/src/backend/catalog/system_views.sql,v
retrieving revision 1.65
diff -c -c -r1.65 system_views.sql
*** src/backend/catalog/system_views.sql    2 Jan 2010 16:57:36 -0000    1.65
--- src/backend/catalog/system_views.sql    25 Apr 2010 02:47:39 -0000
***************
*** 335,347 ****
              S.usesysid,
              U.rolname AS usename,
              S.application_name,
!             S.current_query,
!             S.waiting,
              S.xact_start,
              S.query_start,
!             S.backend_start,
!             S.client_addr,
!             S.client_port
      FROM pg_database D, pg_stat_get_activity(NULL) AS S, pg_authid U
      WHERE S.datid = D.oid AND 
              S.usesysid = U.oid;
--- 335,347 ----
              S.usesysid,
              U.rolname AS usename,
              S.application_name,
!             S.client_addr,
!             S.client_port,
!             S.backend_start,
              S.xact_start,
              S.query_start,
!             S.waiting,
!             S.current_query
      FROM pg_database D, pg_stat_get_activity(NULL) AS S, pg_authid U
      WHERE S.datid = D.oid AND 
              S.usesysid = U.oid;
Index: src/test/regress/expected/rules.out
===================================================================
RCS file: /cvsroot/pgsql/src/test/regress/expected/rules.out,v
retrieving revision 1.154
diff -c -c -r1.154 rules.out
*** src/test/regress/expected/rules.out    29 Dec 2009 20:11:45 -0000    1.154
--- src/test/regress/expected/rules.out    25 Apr 2010 02:47:40 -0000
***************
*** 1289,1295 ****
   pg_rules                 | SELECT n.nspname AS schemaname, c.relname AS tablename, r.rulename, pg_get_ruledef(r.oid)
ASdefinition FROM ((pg_rewrite r JOIN pg_class c ON ((c.oid = r.ev_class))) LEFT JOIN pg_namespace n ON ((n.oid =
c.relnamespace)))WHERE (r.rulename <> '_RETURN'::name);
 
   pg_settings              | SELECT a.name, a.setting, a.unit, a.category, a.short_desc, a.extra_desc, a.context,
a.vartype,a.source, a.min_val, a.max_val, a.enumvals, a.boot_val, a.reset_val, a.sourcefile, a.sourceline FROM
pg_show_all_settings()a(name, setting, unit, category, short_desc, extra_desc, context, vartype, source, min_val,
max_val,enumvals, boot_val, reset_val, sourcefile, sourceline);
 
   pg_shadow                | SELECT pg_authid.rolname AS usename, pg_authid.oid AS usesysid, pg_authid.rolcreatedb AS
usecreatedb,pg_authid.rolsuper AS usesuper, pg_authid.rolcatupdate AS usecatupd, pg_authid.rolpassword AS passwd,
(pg_authid.rolvaliduntil)::abstimeAS valuntil, s.setconfig AS useconfig FROM (pg_authid LEFT JOIN pg_db_role_setting s
ON(((pg_authid.oid = s.setrole) AND (s.setdatabase = (0)::oid)))) WHERE pg_authid.rolcanlogin;
 
!  pg_stat_activity         | SELECT s.datid, d.datname, s.procpid, s.usesysid, u.rolname AS usename,
s.application_name,s.current_query, s.waiting, s.xact_start, s.query_start, s.backend_start, s.client_addr,
s.client_portFROM pg_database d, pg_stat_get_activity(NULL::integer) s(datid, procpid, usesysid, application_name,
current_query,waiting, xact_start, query_start, backend_start, client_addr, client_port), pg_authid u WHERE ((s.datid =
d.oid)AND (s.usesysid = u.oid));
 
   pg_stat_all_indexes      | SELECT c.oid AS relid, i.oid AS indexrelid, n.nspname AS schemaname, c.relname, i.relname
ASindexrelname, pg_stat_get_numscans(i.oid) AS idx_scan, pg_stat_get_tuples_returned(i.oid) AS idx_tup_read,
pg_stat_get_tuples_fetched(i.oid)AS idx_tup_fetch FROM (((pg_class c JOIN pg_index x ON ((c.oid = x.indrelid))) JOIN
pg_classi ON ((i.oid = x.indexrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = ANY
(ARRAY['r'::"char",'t'::"char"]));
 
   pg_stat_all_tables       | SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_numscans(c.oid) AS
seq_scan,pg_stat_get_tuples_returned(c.oid) AS seq_tup_read, (sum(pg_stat_get_numscans(i.indexrelid)))::bigint AS
idx_scan,((sum(pg_stat_get_tuples_fetched(i.indexrelid)))::bigint + pg_stat_get_tuples_fetched(c.oid)) AS
idx_tup_fetch,pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS n_tup_upd,
pg_stat_get_tuples_deleted(c.oid)AS n_tup_del, pg_stat_get_tuples_hot_updated(c.oid) AS n_tup_hot_upd,
pg_stat_get_live_tuples(c.oid)AS n_live_tup, pg_stat_get_dead_tuples(c.oid) AS n_dead_tup,
pg_stat_get_last_vacuum_time(c.oid)AS last_vacuum, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum,
pg_stat_get_last_analyze_time(c.oid)AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze FROM
((pg_classc 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_bgwriter         | SELECT pg_stat_get_bgwriter_timed_checkpoints() AS checkpoints_timed,
pg_stat_get_bgwriter_requested_checkpoints()AS checkpoints_req, pg_stat_get_bgwriter_buf_written_checkpoints() AS
buffers_checkpoint,pg_stat_get_bgwriter_buf_written_clean() AS buffers_clean, pg_stat_get_bgwriter_maxwritten_clean()
ASmaxwritten_clean, pg_stat_get_buf_written_backend() AS buffers_backend, pg_stat_get_buf_alloc() AS buffers_alloc;
 
--- 1289,1295 ----
   pg_rules                 | SELECT n.nspname AS schemaname, c.relname AS tablename, r.rulename, pg_get_ruledef(r.oid)
ASdefinition FROM ((pg_rewrite r JOIN pg_class c ON ((c.oid = r.ev_class))) LEFT JOIN pg_namespace n ON ((n.oid =
c.relnamespace)))WHERE (r.rulename <> '_RETURN'::name);
 
   pg_settings              | SELECT a.name, a.setting, a.unit, a.category, a.short_desc, a.extra_desc, a.context,
a.vartype,a.source, a.min_val, a.max_val, a.enumvals, a.boot_val, a.reset_val, a.sourcefile, a.sourceline FROM
pg_show_all_settings()a(name, setting, unit, category, short_desc, extra_desc, context, vartype, source, min_val,
max_val,enumvals, boot_val, reset_val, sourcefile, sourceline);
 
   pg_shadow                | SELECT pg_authid.rolname AS usename, pg_authid.oid AS usesysid, pg_authid.rolcreatedb AS
usecreatedb,pg_authid.rolsuper AS usesuper, pg_authid.rolcatupdate AS usecatupd, pg_authid.rolpassword AS passwd,
(pg_authid.rolvaliduntil)::abstimeAS valuntil, s.setconfig AS useconfig FROM (pg_authid LEFT JOIN pg_db_role_setting s
ON(((pg_authid.oid = s.setrole) AND (s.setdatabase = (0)::oid)))) WHERE pg_authid.rolcanlogin;
 
!  pg_stat_activity         | SELECT s.datid, d.datname, s.procpid, s.usesysid, u.rolname AS usename,
s.application_name,s.client_addr, s.client_port, s.backend_start, s.xact_start, s.query_start, s.waiting,
s.current_queryFROM pg_database d, pg_stat_get_activity(NULL::integer) s(datid, procpid, usesysid, application_name,
current_query,waiting, xact_start, query_start, backend_start, client_addr, client_port), pg_authid u WHERE ((s.datid =
d.oid)AND (s.usesysid = u.oid));
 
   pg_stat_all_indexes      | SELECT c.oid AS relid, i.oid AS indexrelid, n.nspname AS schemaname, c.relname, i.relname
ASindexrelname, pg_stat_get_numscans(i.oid) AS idx_scan, pg_stat_get_tuples_returned(i.oid) AS idx_tup_read,
pg_stat_get_tuples_fetched(i.oid)AS idx_tup_fetch FROM (((pg_class c JOIN pg_index x ON ((c.oid = x.indrelid))) JOIN
pg_classi ON ((i.oid = x.indexrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = ANY
(ARRAY['r'::"char",'t'::"char"]));
 
   pg_stat_all_tables       | SELECT c.oid AS relid, n.nspname AS schemaname, c.relname, pg_stat_get_numscans(c.oid) AS
seq_scan,pg_stat_get_tuples_returned(c.oid) AS seq_tup_read, (sum(pg_stat_get_numscans(i.indexrelid)))::bigint AS
idx_scan,((sum(pg_stat_get_tuples_fetched(i.indexrelid)))::bigint + pg_stat_get_tuples_fetched(c.oid)) AS
idx_tup_fetch,pg_stat_get_tuples_inserted(c.oid) AS n_tup_ins, pg_stat_get_tuples_updated(c.oid) AS n_tup_upd,
pg_stat_get_tuples_deleted(c.oid)AS n_tup_del, pg_stat_get_tuples_hot_updated(c.oid) AS n_tup_hot_upd,
pg_stat_get_live_tuples(c.oid)AS n_live_tup, pg_stat_get_dead_tuples(c.oid) AS n_dead_tup,
pg_stat_get_last_vacuum_time(c.oid)AS last_vacuum, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum,
pg_stat_get_last_analyze_time(c.oid)AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze FROM
((pg_classc 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_bgwriter         | SELECT pg_stat_get_bgwriter_timed_checkpoints() AS checkpoints_timed,
pg_stat_get_bgwriter_requested_checkpoints()AS checkpoints_req, pg_stat_get_bgwriter_buf_written_checkpoints() AS
buffers_checkpoint,pg_stat_get_bgwriter_buf_written_clean() AS buffers_clean, pg_stat_get_bgwriter_maxwritten_clean()
ASmaxwritten_clean, pg_stat_get_buf_written_backend() AS buffers_backend, pg_stat_get_buf_alloc() AS buffers_alloc;