Re: Postmaster holding unlinked files for pg_largeobject table

Excerpts from Alexander Shulgin's message of vie jun 03 17:45:28 -0400 2011:

> There were about 450 such (or similar) files, all of them having /2613 in the filename.  Since 2613 is a regclass of
pg_largeobjectand we are indeed working with quite a few large objects in that DB so this is where our problem lies we
suspect.
> 
> Restarting PostgreSQL obviously helps the issue and the disk space occupied by those unlinked files (about 63GB
actually)is reclaimed.
 
> 
> So what happens on that host is that we drop/restore a fresh version of the DB from the production host, followed by
amigration script which among other things loads around 16GB of data files as large objects.  This happens nightly.
 

What surprises me is that the open references remain after a database
drop.  Surely this means that no backends keep open file descriptors to
any table in that database, because there are no connections.

I also requested Alexander to run a checkpoint and see if that made the
FDs go away (on the theory that bgwriter could be the culprit) -- no dice.

-- 
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
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