Обсуждение: Problems monitoring DB activity

Hello,

When I do the following:

SELECT * FROM pg_catalog.pg_stat_activity;

The current_query and query_start columns are always empty. Obviously
this makes it hard to monitor problems with the various admin tools, etc.

I'm guessing there's a setting or something that needs updated, I just
need a point in the right direction. DB is 7.4.2

Thanks

On Fri, Oct 08, 2004 at 09:54:08AM -0400, Doug Y wrote:
>
> SELECT * FROM pg_catalog.pg_stat_activity;
>
> The current_query and query_start columns are always empty. Obviously
> this makes it hard to monitor problems with the various admin tools, etc.

Does postgresql.conf have stats_command_string = true?

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

Michael Fuhr wrote:

>On Fri, Oct 08, 2004 at 09:54:08AM -0400, Doug Y wrote:
>
>
>>SELECT * FROM pg_catalog.pg_stat_activity;
>>
>>The current_query and query_start columns are always empty. Obviously
>>this makes it hard to monitor problems with the various admin tools, etc.
>>
>>
>
>Does postgresql.conf have stats_command_string = true?
>
Thanks, setting that did the trick....  whats the performance hit for
having it enabled?

On Fri, Oct 08, 2004 at 10:46:56AM -0400, Doug Y wrote:
> Michael Fuhr wrote:
> >
> >Does postgresql.conf have stats_command_string = true?
> >
> Thanks, setting that did the trick....  whats the performance hit for
> having it enabled?

I haven't done any tests to determine the performance penalty; maybe
one of the developers or somebody who's done some benchmarks can
comment.

The "Annotated postgresql.conf and Global User Configuration (GUC)
Guide"[1] says that "Enabling statistics collection costs a small
amount of time per query, but is invaluable for debugging and
performance tuning."

[1] http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

Sounds like the Oracle parameter TIMED_STATISTICS.  Costs you soo little
in performance, but saves you a pile in troubleshooting.  Many DBA's
still set it to false to "save the expense".  Nice to know the same
exists here.


Dick Goulet
Senior Oracle DBA
Oracle Certified 8i DBA
-----Original Message-----
From: Michael Fuhr [mailto:mike@fuhr.org]
Sent: Friday, October 08, 2004 11:15 AM
To: Doug Y
Cc: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] Problems monitoring DB activity

On Fri, Oct 08, 2004 at 10:46:56AM -0400, Doug Y wrote:
> Michael Fuhr wrote:
> >
> >Does postgresql.conf have stats_command_string = true?
> >
> Thanks, setting that did the trick....  whats the performance hit for
> having it enabled?

I haven't done any tests to determine the performance penalty; maybe one
of the developers or somebody who's done some benchmarks can comment.

The "Annotated postgresql.conf and Global User Configuration (GUC)
Guide"[1] says that "Enabling statistics collection costs a small amount
of time per query, but is invaluable for debugging and performance
tuning."

[1]
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

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