Thread: Usage of pg_stat_database
If I read the xact_commit field returned by "Select * from pg_stat_database" multiple times, and then average the difference between consecutive values, would this give an approx idea about the transactions per second in my database?
Does this figure include the number of select statements being executed in the db?
With regards
Amitabh
On Mon, 2011-10-24 at 19:34 +0530, Amitabh Kant wrote:
> If I read the xact_commit field returned by "Select * from
> pg_stat_database" multiple times, and then average the difference
> between consecutive values, would this give an approx idea about the
> transactions per second in my database?
Yes, approximately. It relies on the stats messages.
> Does this figure include the number of select statements being
> executed in the db?
>
Yes, a quick test shows that select statements count as well. However,
it seems that very simple selects, like "SELECT 1" might not send the
stats messages right away, and they might end up getting lost.
Regards,
Jeff Davis
Thanks Jeff. This should help in getting a fairly approximate values.
Amitabh
On Fri, Oct 28, 2011 at 11:24 AM, Jeff Davis <pgsql@j-davis.com> wrote:
On Mon, 2011-10-24 at 19:34 +0530, Amitabh Kant wrote:Yes, approximately. It relies on the stats messages.
> If I read the xact_commit field returned by "Select * from
> pg_stat_database" multiple times, and then average the difference
> between consecutive values, would this give an approx idea about the
> transactions per second in my database?Yes, a quick test shows that select statements count as well. However,
> Does this figure include the number of select statements being
> executed in the db?
>
it seems that very simple selects, like "SELECT 1" might not send the
stats messages right away, and they might end up getting lost.
Regards,
Jeff Davis