Re: Possible explanations for catastrophic performace deterioration?

[Carlos Moreno <moreno_pg(at)mochima(dot)com>]

> > I don't understand this argument --- the newer system has actually
> > less memory than the old one;  how could it fit there and not on the
> > old one?  Plus, how could dropping-recreating the database on the same
> > machine change the fact that the entire dataset entirely fit or not in
> > memory??
>
> Because on the older server it is bloated, while on the new one it is
> fresh thus no dead tuples.

Wait a second --- am I correct in understanding then that the bloating
you guys are referring to occurs *in memory*??

My mind has been operating under the assumption that bloating only
occurs on disk, and never in memory --- is there where my logic is
mistaken?

> > I wonder if I should then periodically run a vacuum full --- say, once
> > a week?  Once a month?
>
> Never.  What you need to do is make sure your FSM settings
> (fsm_max_pages in particular) are high enough, and that you VACUUM (not
> full) frequently enough.

Noted.

Thanks!

Carlos
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