Re: database question

On Mon, Sep 29, 2008 at 8:21 AM, <john(dot)crawford(at)sirsidynix(dot)com> wrote:
> Hi all I have been experiencing some strange behaviour on my postgres
> DB. I am VERY new to PG so bear with me as what I am going to ask is
> all probably very basic to you guys.
> First off over the last couple of weeks we have been seeing in the
> dir /var/lib/pgsql/data/base/16450 some large file creations, so for
> example
>
> -rw------- 1 postgres postgres 1073741824 Sep 29 15:15 2683
> -rw------- 1 postgres root 1073741824 Sep 29 15:15 2613.77
> -rw------- 1 postgres root 1073741824 Sep 29 15:15 2613.83
>
> What are these files and why have they suddenly started to be created
> and why so large?

PostgreSQL automatically splits table files into 1G chunks so it can
run on OSes with file size limits. These are part of the table
identified by the oid 2613. You can find it by looking in pg_class.
Run psql -E and do \d and you'll see the queries that psql uses to
create its output, and you can muck about with them to see which are
which.

Also, the contrib module oid2name will tell you these things from the
shell / CLI.