Re: PostgreSQL strugling during high load

> > ... So contents of database changes very fast. Problem is that when
> > pg_autovacuum does vacuum those changes slows down too much.
>
> The "vacuum cost" parameters can be adjusted to make vacuums fired
> by pg_autovacuum less of a burden. I haven't got any specific numbers
> to suggest, but perhaps someone else does.

It looks like that not only vacuum causes our problems. vacuum_cost
seems to lower vacuum impact but we are still noticing slow queries "storm".
We are logging queries that takes >2000ms to process.
And there is quiet periods and then suddenly 30+ slow queries appears in
log within the same second. What else could cause such behaviour? WAL log
switch? One WAL file seems to last <1 minute.

And also in slow queries log only function call is shown. Maybe it is
possible
to get exact query which slows everything down in the serverlog?

Thanks,

Mindaugas