Determine query run-time from pg_* tables

Ow Mun Heng wrote:

Hi,

Is there a method to obtain the query's runtime from any of the pg_*
tables?

No. You can use log_durations and log_statement for that. We don't
store that info in tables.

Right now, I'm only seeing the backend_start_time (from
pg_stat_activity) (and I'm also not sure how to interpret this.

This is the time that the session was started. Nothing to do with the
query itself.

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

On Oct 23, 2007, at 8:43 AM, Alvaro Herrera wrote:

Ow Mun Heng wrote:

Hi,

Is there a method to obtain the query's runtime from any of the pg_*
tables?

No. You can use log_durations and log_statement for that. We don't
store that info in tables.

Right now, I'm only seeing the backend_start_time (from
pg_stat_activity) (and I'm also not sure how to interpret this.

This is the time that the session was started. Nothing to do with the
query itself.

query_start does, however, give you the time that the query started.
I use something like

SELECT procpid, client_addr, to_char(now() - query_start, 'DD
HH24:MI:SS') as query_time, current_query
FROM pg_stat_activity
ORDER BY query_time DESC;

To get a snapshot view of what's currently running in our databases.

Erik Jones

Software Developer | Emma®
erik@myemma.com
800.595.4401 or 615.292.5888
615.292.0777 (fax)

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On Tue, 2007-10-23 at 09:28 -0500, Erik Jones wrote:

Ow Mun Heng wrote:

Hi,

Is there a method to obtain the query's runtime from any of the pg_*
tables?

query_start does, however, give you the time that the query started.
I use something like

SELECT procpid, client_addr, to_char(now() - query_start, 'DD
HH24:MI:SS') as query_time, current_query
FROM pg_stat_activity
ORDER BY query_time DESC;

Thanks for this.. but I found that this query doesn't really do much for
the query_time. It's always 00 for a long runnig query >1min.

I've re-wrote it using

SELECT procpid, client_addr, now() - query_start as query_time,
current_query
FROM pg_stat_activity
ORDER BY query_time DESC;

the to_char doesn't really do much for me..

Thanks for the pointer though.. It led me to the right direction.