Re: Patch to remove sort files, temp tables, unreferenced files

I agree with Tom's arguments ...

On Wed, 30 May 2001, Bruce Momjian wrote:

>
> OK, Tom doesn't like the majority of my patch.  I think it has value.
> Would others like to comment?
>
>
> > Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > >> No we don't.  I'm not convinced that we have a problem at all anymore.
> >
> > > We already know that crashes will leave these files around, and as we
> > > start using file versioning for CLUSTER and DROP COLUMN, I expect those
> > > orphaned files to continue.
> >
> > I don't.  The intention (not yet implemented, but Vadim's referred to it
> > repeatedly) is that relation file creation/deletion will be logged in
> > WAL, and so it can be redone or undone after a crash.  That seems a much
> > more secure approach than anything you've proposed in this thread.
> >
> > Temp files won't be logged in WAL, but a startup-time cleanup seems
> > sufficient to deal with them.
> >
> > > You are correct.  I didn't realized that after I check the shared memory
> > > for the pid, another backend could start with the pid I was checking and
> > > create a sort file.  The sort code doesn't do O_EXCL,
> >
> > ... quite deliberately ... you might want to add a comment to that
> > effect in OpenTemporaryFile.
> >
> >             regards, tom lane
> >
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> >
>
> --
>   Bruce Momjian                        |  http://candle.pha.pa.us
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