Re: COPY, lock release and MVCC

On Wed, 2020-05-13 at 19:29 +0530, Amit Kapila wrote:
> > > > > On Fri, May 8, 2020 at 4:58 AM Laurenz Albe <laurenz.albe@cybertec.at> wrote:
> > > > > > I happened to notice that COPY TO releases the ACCESS SHARE lock
> > > > > > on the table right when the command ends rather than holding it
> > > > > > until the end of the transaction:
> > 
> > Here is a patch.
> > 
> 
> - /*
> - * Close the relation. If reading, we can release the AccessShareLock we
> - * got; if writing, we should hold the lock until end of transaction to
> - * ensure that updates will be committed before lock is released.
> - */
> - if (rel != NULL)
> - table_close(rel, (is_from ? NoLock : AccessShareLock));
> + table_close(rel, NoLock);
> 
> I wonder why you have removed (rel != NULL) check?

That was just unexcusable sloppiness, nothing more.

Here is a fixed patch.

Yours,
Laurenz Albe