Re: Odd system-column handling in postgres_fdw join pushdown patch

On Fri, Apr 15, 2016 at 10:17 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Fri, Apr 15, 2016 at 12:16 PM, Ashutosh Bapat
> <ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
> > The testcases had tableoid::regclass which outputs the foreign table's
> local
> > name, which won't change across runs. Isn't that so?
>
> [rhaas pgsql]$ grep 16444 ~/Downloads/postgres-fdw-syscol-zap-ab.patch
> + Remote SQL: SELECT r1.c1, CASE WHEN r1.* IS NOT NULL THEN 0
> END, CASE WHEN r1.* IS NOT NULL THEN 0 END, CASE WHEN r1.* IS NOT NULL
> THEN 0 END, CASE WHEN r1.* IS NOT NULL THEN 16444 END, CASE WHEN r2.*
> IS NOT NULL THEN 0 END, CASE WHEN r2.* IS NOT NULL THEN 16447 END,
> r2.c1 FROM ("S 1"."T 3" r1 INNER JOIN "S 1"."T 4" r2 ON (TRUE)) WHERE
> ((r1.c1 = r2.c1)) ORDER BY r1.c1 ASC NULLS LAST
> + Remote SQL: SELECT r1.c1, CASE WHEN r1.* IS NOT NULL THEN
> 16444 END, CASE WHEN r2.* IS NOT NULL THEN 16447 END, r2.c1 FROM ("S
> 1"."T 3" r1 LEFT JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) ORDER BY
> r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST
> + Remote SQL: SELECT r1.c1, CASE WHEN r1.* IS NOT NULL THEN
> 16444 END, CASE WHEN r2.* IS NOT NULL THEN 16447 END, r2.c1 FROM ("S
> 1"."T 3" r1 FULL JOIN "S 1"."T 4" r2 ON (((r1.c1 = r2.c1)))) ORDER BY
> r1.c1 ASC NULLS LAST, r2.c1 ASC NULLS LAST
>
> Where do you think 16444 and 16447 are coming from here?
>

Ah! Sorry, it's the explain output.
--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company