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

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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