Thread: size difference between du and PG_CLASS

size difference between du and PG_CLASS

From
"Lee Wu"
Date:

Hi All,

 

We have a big difference between du and PG_CLASS:

 

du -hs ./base/17613

21G     ./base/17613

 

select sum(relpages)*8/1024/1024 from pg_class;

 ?column?

----------

       11

(1 row)

 

I am sure I run the select under the right database (17613).

 

I know there are some files under:

du -hs base/17613/pgsql_tmp

1.7G    base/17613/pgsql_tmp

 

But the difference is still around 8G (21G – 11G – 1.7G).

 

When I check timestamp on files under directory 17613, I found there are many old relfilenode which do not exist

in the pg_class any more. We had bounced the PG server, those files are still there.

 

Does PG remove those files which are not longer used by PG after server bounce?

 

Which files can I safely delete?

 

Thanks,

 

PS: PG version 7.3.2 and OS version Red Hat Linux release 7.3 (Valhalla)

Re: size difference between du and PG_CLASS

From
Tom Lane
Date:
"Lee Wu" <Lwu@mxlogic.com> writes:
> in the pg_class any more. We had bounced the PG server, those files are
> still there.

I am starting to think that a lot of your problems are self-induced.
You should not "bounce the PG server" every time you think maybe there's
something wrong.

            regards, tom lane