Re: 9.4 -> 9.5 dump size reduction

On Thu, 11 Feb 2016 23:48:53 -0500,
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Seb <spluque(at)gmail(dot)com> writes:
>> I recently upgraded a server from 9.4 to 9.5 (Debian) via
>> pg_upgradecluster. The upgrade finished well, and so far the
>> databases in the upgraded cluster seem in good form. However, I
>> noticed a dramatic reduction in the size of the dump created by the
>> new server. One of the databases was 34G when dumped by the 9.4
>> server is now dumped at 1.1G in the new 9.5 version (using pg_dump
>> -Fc in both cases). What has caused such remarkable improvement?!

> That seems really fishy. Better check to see if all your data is
> still there :-(

Sure enough, upon closer inspection I see that the pgagent job that was
generating these dumps had aborted before finishing. It looks like the
upgrade interrupted the job. I've restarted the agent, reran the job
right away, and now see that the dumps with the new server haven't
changed size, and all data are there.

Sorry for the premature post,

--
Seb