Обсуждение: Current query of the PL/pgsql procedure.

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Current query of the PL/pgsql procedure.

От
Yuri Levinsky
Дата:

Dear ALL,

I am running PL/pgsql procedure with sql statements that taking a long time. I able to see them in the log just after their completion. How can I see currently running SQL statement?  I am able to see in pg_stat_activity only my call to function. Many thanks in advance.

 

Sincerely yours,

 

Description: Celltick logo_highres

Yuri Levinsky, DBA

Celltick Technologies Ltd., 32 Maskit St., Herzliya 46733, Israel

Mobile: +972 54 6107703, Office: +972 9 9710239; Fax: +972 9 9710222

 

Вложения

Re: Current query of the PL/pgsql procedure.

От
Craig James
Дата:
On Sun, Dec 15, 2013 at 8:18 AM, Yuri Levinsky <yuril@celltick.com> wrote:

Dear ALL,

I am running PL/pgsql procedure with sql statements that taking a long time. I able to see them in the log just after their completion. How can I see currently running SQL statement?  I am able to see in pg_stat_activity only my call to function. Many thanks in advance.


pg_stat_activity is the right table, but you have to be the super-user to see queries by others.  Here's what I use:

$ psql -U postgres
postgres=# select procpid, datname, usename, current_query from pg_stat_activity where current_query !~ '<IDLE>';

 Craig

 

Sincerely yours,

 

Description: Celltick logo_highres

Yuri Levinsky, DBA

Celltick Technologies Ltd., 32 Maskit St., Herzliya 46733, Israel

Mobile: +972 54 6107703, Office: +972 9 9710239; Fax: +972 9 9710222

 


Вложения

Re: Current query of the PL/pgsql procedure.

От
hubert depesz lubaczewski
Дата:
On Sun, Dec 15, 2013 at 04:18:18PM +0000, Yuri Levinsky wrote:
> Dear ALL,
> I am running PL/pgsql procedure with sql statements that taking a long
> time. I able to see them in the log just after their completion. How
> can I see currently running SQL statement?  I am able to see in
> pg_stat_activity only my call to function. Many thanks in advance.

pg_stat_activity and pg logs, can't see what your function does
internally.

What you can do, though, is to add some "RAISE LOG" to the function, so
that it will log its progress.

Check this for example:
http://www.depesz.com/2010/03/18/profiling-stored-proceduresfunctions/

Best regards,

depesz
Вложения

Re: Current query of the PL/pgsql procedure.

От
Yuri Levinsky
Дата:
Dear Depesz,
This is very problematic solution: I have to change whole!!! my code to put appropriate comment with query text before
anyquery execution. In addition I would like to know current execution plan, that seems to be impossible. This is very
hardlimitation let's say. In case of production issue I'll just unable to do it: the issue already happening, I can't
stopprocedure and start code change.
 
James,
I saw your reply: I see the function is running, it's just not clear that exactly and how this function doing. 

Sincerely yours,


Yuri Levinsky, DBA
Celltick Technologies Ltd., 32 Maskit St., Herzliya 46733, Israel
Mobile: +972 54 6107703, Office: +972 9 9710239; Fax: +972 9 9710222

-----Original Message-----
From: depesz@depesz.com [mailto:depesz@depesz.com] 
Sent: Monday, December 16, 2013 12:26 PM
To: Yuri Levinsky
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Current query of the PL/pgsql procedure.

On Sun, Dec 15, 2013 at 04:18:18PM +0000, Yuri Levinsky wrote:
> Dear ALL,
> I am running PL/pgsql procedure with sql statements that taking a long 
> time. I able to see them in the log just after their completion. How 
> can I see currently running SQL statement?  I am able to see in 
> pg_stat_activity only my call to function. Many thanks in advance.

pg_stat_activity and pg logs, can't see what your function does internally.

What you can do, though, is to add some "RAISE LOG" to the function, so that it will log its progress.

Check this for example:
http://www.depesz.com/2010/03/18/profiling-stored-proceduresfunctions/

Best regards,

depesz

Re: Current query of the PL/pgsql procedure.

От
Matheus de Oliveira
Дата:

On Sun, Dec 15, 2013 at 2:18 PM, Yuri Levinsky <yuril@celltick.com> wrote:

Dear ALL,

I am running PL/pgsql procedure with sql statements that taking a long time. I able to see them in the log just after their completion. How can I see currently running SQL statement?  I am able to see in pg_stat_activity only my call to function. Many thanks in advance.

 




As noticed, pg_stat_activity will only be able to see the call to that function, not the queries been executed inside the function itself. The same will happen with the logs (configuring GUCs like log_statements or log_min_duration_statement). A solution I have used to solve this issue is either the contrib auto_explain [1] or pg_stat_statements [2]. Both will be able to get the queries executed inside the functions. For that, you will have to configure then (by default they will not track the queries inside):

* for auto_explain: `auto_explain.log_nested_statements = on`
* for pg_stat_statements: `pg_stat_statements.track = all`

The problem you stated about the logs, that it only logs after the execution not during or before, will still remain. Both will "get the query" right after the execution. In your use case auto_explain seems better to use to track, as it can grows with no limit (you will have to control your log file size and auto_explain.log_min_duration to avoid a log flood, though).
 

Best regards,
--
Matheus de Oliveira
Analista de Banco de Dados
Dextra Sistemas - MPS.Br nível F!
www.dextra.com.br/postgres

Re: Current query of the PL/pgsql procedure.

От
Andrew Dunstan
Дата:
On 12/16/2013 05:26 AM, hubert depesz lubaczewski wrote:
> On Sun, Dec 15, 2013 at 04:18:18PM +0000, Yuri Levinsky wrote:
>> Dear ALL,
>> I am running PL/pgsql procedure with sql statements that taking a long
>> time. I able to see them in the log just after their completion. How
>> can I see currently running SQL statement?  I am able to see in
>> pg_stat_activity only my call to function. Many thanks in advance.
> pg_stat_activity and pg logs, can't see what your function does
> internally.
>
> What you can do, though, is to add some "RAISE LOG" to the function, so
> that it will log its progress.
>
> Check this for example:
> http://www.depesz.com/2010/03/18/profiling-stored-proceduresfunctions/
>

Also, the auto-explain module can peer inside functions. See
<http://www.postgresql.org/docs/current/static/auto-explain.html>

cheers

andrew

Re: Current query of the PL/pgsql procedure.

От
Guillaume Lelarge
Дата:
On Mon, 2013-12-16 at 11:42 +0000, Yuri Levinsky wrote:
>  Dear Depesz,
> This is very problematic solution: I have to change whole!!! my code to put appropriate comment with query text
beforeany query execution. In addition I would like to know current execution plan, that seems to be impossible. This
isvery hard limitation let's say. In case of production issue I'll just unable to do it: the issue already happening, I
can'tstop procedure and start code change. 
> James,
> I saw your reply: I see the function is running, it's just not clear that exactly and how this function doing.
>

This blog post
(http://blog.guillaume.lelarge.info/index.php/post/2012/03/31/Profiling-PL/pgsql-functions) can probably help you
profilingyour PL/pgsql functions without modifying them. 

I'm interested in any comments you can have on the log_functions hook
function.

Regards.


--
Guillaume
http://blog.guillaume.lelarge.info
http://www.dalibo.com