In response to "Sergey Konoplev" <gray(dot)ru(at)gmail(dot)com>:
> Hi
>
> I'd like to know how to get information about which PG entities are in
> kernel cache, if possible.
That's going to be specific to the OS you're running.
Unless you're talking about PG's shared_buffers -- if that's the case, have
a look at the pg_buffercache contrib module.
--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/
wmoran(at)collaborativefusion(dot)com
Phone: 412-422-3463x4023