Re: Table refer leak in logical replication

On Mon, Apr 19, 2021 at 12:32 PM Amit Langote <amitlangote09@gmail.com> wrote:
>
> On Sat, Apr 17, 2021 at 10:32 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > On Fri, Apr 16, 2021 at 11:55 AM Michael Paquier <michael@paquier.xyz> wrote:
> > > On Tue, Apr 06, 2021 at 02:25:05PM +0900, Amit Langote wrote:
> > >
> > > Attached is v5 that I am finishing with.  Much more could be done but
> > > I don't want to do something too invasive at this stage of the game.
> > > There are a couple of extra relations in terms of relations opened for
> > > a partitioned table within create_estate_for_relation() when
> > > redirecting to the tuple routing, but my guess is that this would be
> > > better in the long-term.
> > >
> >
> > Hmm, I am not sure if it is a good idea to open indexes needlessly
> > especially when it is not done in the previous code.
> >
> > @@ -1766,8 +1771,11 @@ apply_handle_tuple_routing(ResultRelInfo *relinfo,
> >   slot_getallattrs(remoteslot);
> >   }
> >   MemoryContextSwitchTo(oldctx);
> > +
> > + ExecOpenIndices(partrelinfo_new, false);
> >   apply_handle_insert_internal(partrelinfo_new, estate,
> >   remoteslot_part);
> > + ExecCloseIndices(partrelinfo_new);
> >   }
> >
> > It seems you forgot to call open indexes before apply_handle_delete_internal.
> >
> > I am not sure if it is a good idea to do the refactoring related to
> > indexes or other things to fix a minor bug in commit 1375422c. It
> > might be better to add a simple fix like what Hou-San has originally
> > proposed [1] because even using ExecInitResultRelation might not be
> > the best thing as it is again trying to open a range table which we
> > have already opened in logicalrep_rel_open.
>
> FWIW, I agree with fixing this bug of 1375422c in as least scary
> manner as possible.  Hou-san proposed that we add the ResultRelInfo
> that apply_handle_{insert|update|delete} initialize themselves to
> es_opened_result_relations.  I would prefer that only
> ExecInitResultRelation() add anything to es_opened_result_relations()
> to avoid future maintenance problems.  Instead, a fix as simple as the
> Hou-san's proposed fix would be to add a ExecCloseResultRelations()
> call at the end of each of apply_handle_{insert|update|delete}.
>

Yeah, that will work too but might look a bit strange. BTW, how that
is taken care of for ExecuteTruncateGuts? I mean we do add rels there
like Hou-San's patch without calling ExecCloseResultRelations, the
rels are probably closed when we close the relation in worker.c but
what about memory for the list?

-- 
With Regards,
Amit Kapila.