Re: Postmaster holding unlinked files for pg_largeobject table

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Mon, Jun 6, 2011 at 12:30 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> On reflection I think this behavior is probably limited to the case
>> where we've done what we used to call a "blind write" of a block that
>> is unrelated to our database or tables. For normal SQL-driven accesses,
>> there's a relcache entry, and flushing of that entry will lead to
>> closure of associated files. I wonder whether we should go back to
>> forcibly closing the FD after a blind write. This would suck if a
>> backend had to do many dirty-buffer flushes for the same relation,
>> but hopefully the bgwriter is doing most of those. We'd want to make
>> sure such forced closure *doesn't* occur in the bgwriter. (If memory
>> serves, it has a checkpoint-driven closure mechanism instead.)

> Instead of closing them immediately, how about flagging the FD and
> closing all the flagged FDs at the end of each query, or something
> like that?

Hmm, there's already a mechanism for closing "temp" FDs at the end of a
query ... maybe blind writes could use temp-like FDs?

regards, tom lane