RE: row filtering for logical replication

On Monday, January 31, 2022 9:02 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
>
> On Mon, Jan 31, 2022 at 1:08 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > On Mon, Jan 31, 2022 at 7:27 AM houzj(dot)fnst(at)fujitsu(dot)com
> > <houzj(dot)fnst(at)fujitsu(dot)com> wrote:
> > >
> > > On Monday, January 31, 2022 8:53 AM Peter Smith
> <smithpb2250(at)gmail(dot)com> wrote:
> > > >
> > > > PSA v73*.
> > > >
> > > > (A rebase was needed due to recent changes in tab-complete.c.
> > > > Otherwise, v73* is the same as v72*).
> > >
> > > Thanks for the rebase.
> > > Attach the V74 patch set which did the following changes:
> > >
> >
> > Few comments:
> > =============
> >
>
> Few more minor comments:
> 1.
> + if (relentry->attrmap)
> + {
> + TupleDesc tupdesc = RelationGetDescr(relation); TupleTableSlot
> + *tmp_slot = MakeTupleTableSlot(tupdesc,
> + &TTSOpsVirtual);
> +
> + new_slot = execute_attr_map_slot(relentry->attrmap,
> + new_slot,
> + tmp_slot);
>
> I think we don't need these additional variables tupdesc and tmp_slot.
> You can directly use MakeTupleTableSlot instead of tmp_slot, which will make
> this and nearby code look better.

Changed.

> 2.
> + if (pubrinfo->pubrelqual)
> + appendPQExpBuffer(query, " WHERE (%s)", pubrinfo->pubrelqual);
> + appendPQExpBufferStr(query, ";\n");
>
> Do we really need additional '()' for rwo filter expression here? See the below
> output from pg_dump:
>
> ALTER PUBLICATION pub1 ADD TABLE ONLY public.t1 WHERE ((c1 < 100));

I will investigate this and change this later if needed.

> 3.
> + /* row filter (if any) */
> + if (pset.sversion >= 150000)
> + {
> + if (!PQgetisnull(result, i, 1))
> + appendPQExpBuffer(&buf, " WHERE %s", PQgetvalue(result, i, 1)); }
>
> I don't think we need this version check if while forming query we use NULL as
> the second column in the corresponding query for v < 150000.

Changed.

Attach the V75 patch set which address the above, Amit's[1] and Greg's[2][3] comments.

The new version patch also includes the following changes:

- run pgindent
- adjust some comments
- remove some unnecessary ExecClearTuple
- slightly improve the row filter of toast case by removing some unnecessary
memory allocation and directly return the modified new slot instead of
copying it again.

[1] https://www.postgresql.org/message-id/CAA4eK1LjyiPkwOki3n%2BQfORmBQLUvsvBfifhZMh%2BquAJTuRU_w%40mail.gmail.com
[2] https://www.postgresql.org/message-id/CAJcOf-fR_BKHNuz7AXCWuk40ESVOr%3DDkXf3evbNNi4M4V_5agQ%40mail.gmail.com
[3] https://www.postgresql.org/message-id/CAJcOf-fR_BKHNuz7AXCWuk40ESVOr%3DDkXf3evbNNi4M4V_5agQ%40mail.gmail.com

Best regards,
Hou zj