Re: File leak?

Tom Lane wrote:
> Heikki Linnakangas <hlinnaka@iki.fi> writes:
> > On Sat, 12 Jun 2004, Tom Lane wrote:
> >> Heikki Linnakangas <hlinnaka@iki.fi> writes:
> >>> I wonder if we could clean up those lost files on database recovery or
> >>> vacuum.
> >> 
> >> There is a TODO for this, but it seems exceedingly low priority to me.
> 
> > Are you sure? I read through the TODO list but couldn't find it.
> 
> Well, there used to be: 7.4 TODO has
> 
> * Remove unreferenced table files and temp tables during database vacuum
>   or postmaster startup (Bruce)
> 
> Now that I think about it, I believe Bruce recently removed this on my
> advice; I was thinking that the problem shouldn't occur anymore now that

True.

> we WAL-log file creation and deletion.  But actually the present form of
> the WAL entries doesn't ensure that a file created by a transaction that
> crashes before committing will go away, because file deletion actions
> are only logged (and replayed) at transaction commit/abort.  So it
> probably should go back in.  Or else we could add more WAL logging

Wording updated to:

* Remove unreferenced table files created by a transactions that were in-progress when the server crashed

> (viz, log at the instant of file creation, and the replayer would have
> to keep track of whether it sees the creating transaction commit and
> delete the file if not).

I don't see how we could WAL log it because we don't fsync the WAL until
our transaction completes, right, or are you thinking we would do a
special fsync when we add the record?

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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