Re: why so many open files?

hubert depesz lubaczewski <depesz@depesz.com> writes:
> why backend process from one database has opened files from other databases?

That's not very surprising at all: a backend might have to write out a
dirty buffer in order to reclaim the buffer for re-use, and which
database the page is from doesn't enter into that.

What does seem surprising is that it's had to do that quite a lot.
Is this an old PG version without a bgwriter process?  In a properly
functioning recent release, I'd expect only the bgwriter to have a
really eclectic mix of open files.

            regards, tom lane