To: pgsql-docs@postgresql.org
From: Mark Stosberg <mark@summersault.com>
Subject: Re: pg_dump docs should mention TMPDIR
Date: Wed, 3 May 2006 18:05:23 +0000 (UTC)
Lines: 35
Message-ID: <slrne5hvn5.aki.mark@simba.summersault.com>
References: <slrne5eona.aki.mark@simba.summersault.com>
	<17708.1146678550@sss.pgh.pa.us>
User-Agent: slrn/0.9.8.0 (Linux)

On 2006-05-03, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Mark Stosberg <mark@summersault.com> writes:
>> A suggested addition to the pg_dump docs:
>> This would be an extension to the documentation for the "tar" format:
>
>> The tar format needs some space to create temporary files. By default
>> "/tmp" is used. On systems with small "/tmp" partitions, set the
>> "TMPDIR" environment variable to a location with more space, such as
>> "/usr/tmp".
>
> There is no reference to TMPDIR in the pg_dump code.  It may be that
> tmpfile() pays attention to such an environment variable on your
> machine, but there's nothing about it in the Single Unix Spec.

Yes, on FreeBSD "man tmpfile()" documents the use of TMPDIR.

If TMPDIR isn't being respected globally, perhaps there /should/ be
logic in the code to make that so. Even on fairly modern FreeBSD
installs, sometimes "/tmp" only has 256 MB of room. There really should
be a reliable way to specify a different temporary directory.

>> Also, I would like it if the pg_dump docs more assertively recommended
>> one of the "tar" or "custom" formats. They seem very similiar.
>
> Yeah.  I think it should specifically recommend custom format.  The only
> reason for using tar format would be if you want to process the file
> later with something other than pg_restore.

Thanks for the recommendation. 

Is that any concern that over time newer pg_restore's won't read old
"custom" formats? That would be my only worry-- that the data would be
locked in a binary format which becomes unsupported.

    Mark