Re: logical decoding : exceeded maxAllocatedDescs for .spill files

On Wed, 20 Nov 2019 at 13:10, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Tue, Nov 19, 2019 at 4:58 PM Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com> wrote:
> >
> > On Tue, 19 Nov 2019 at 14:07, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > >
> > >
> > > Have you tried by injecting some error? After getting the error
> > > mentioned above in email, when I retried the same query, I got the
> > > below message.
> > >
> > > postgres=# SELECT 1 from
> > > pg_logical_slot_get_changes('regression_slot', NULL,NULL) LIMIT 1;
> > > ERROR: could not remove file
> > > "pg_replslot/regression_slot/xid-1693-lsn-0-18000000.spill" during
> > > removal of pg_replslot/regression_slot/xid*: Permission denied
> > >
> > > And, then I tried to drop the replication slot and I got below error.
> > > postgres=# SELECT * FROM pg_drop_replication_slot('regression_slot');
> > > ERROR: could not rename file "pg_replslot/regression_slot" to
> > > "pg_replslot/regression_slot.tmp": Permission denied
> > >
> > > It might be something related to Windows
> >
> > Oh ok, I missed the fact that on Windows we can't delete the files
> > that are already open, unlike Linux/Unix.
> >
>
> See comment in pgunlink() "We need to loop because even though
> PostgreSQL uses flags that allow unlink while the file is open, other
> applications might have the file
> open without those flags.". Can you once see if there is any flag
> that you have missed to pass to allow this? If there is nothing we
> can do about it, then we might need to use some different API or maybe
> define a new API that can handle this.

Hmm, looks like there is one such flag: FILE_SHARE_DELETE. When file
is opened with this flag, other processes can delete as well as rename
the file.

But it turns out that in pgwin32_open(), we already use
FILE_SHARE_DELETE. So, this is again confusing.

--
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company