Shanmugasundaram Doraisamy wrote:
> Dear Group,
> We have a java front-end for postgresql 3.4.
Hopefully 7.3.4, otherwise upgrade :-)
> When
> we monitor the system usage using top we find couple of postmasters
> taking up close to 90% of the CPU time in total. I would like to know
> which are the queries that are currently running at this point of time.
> How do we do this??
Read the "monitoring activity" chapter for full details, but if you have
statistics gathering turned on try selecting from pg_stat_activity. You
might also be able to see backend status with ps / top set to show the
whole command-line.
> Another thing that I have noticed is that when I
> give df -h, I find there is a partition /dev/shm which is somewhere in
> the range of about 128MB and never used. What is this supposed to be.
> Is it being not used a good sign or am I loosing on my performance? How
> do we get it to be used by the database if it will help improve the
> performance.
Almost certainly shared-mem (you don't say what system you're on) and it
will be used, regardless of what df says - increase the settings in your
postgresql.conf beyond 128MB and you'll see postgresql fail to start.
--
Richard Huxton
Archonet Ltd