On 2021/04/16 14:20, Kyotaro Horiguchi wrote:
At Fri, 16 Apr 2021 11:54:16 +0900, Fujii Masao <masao.fu...@oss.nttdata.com>
wrote in
On 2021/04/16 9:15, Bharath Rupireddy wrote:
On Thu, Apr 15, 2021 at 8:19 PM Fujii Masao <masao.fu...@oss.nttdata.com>
wrote:
On 2021/04/14 12:54, Bharath Rupireddy wrote:
IMHO, we can push all the TRUNCATE options (ONLY, RESTRICTED, CASCADE,
RESTART/CONTINUE IDENTITY), because it doesn't have any major
challenge(implementation wise) unlike pushing some clauses in
SELECT/UPDATE/DELETE and we already do this on the master. It doesn't
look good and may confuse users, if we push some options and restrict
others. We should have an explicit note in the documentation saying we
push all these options to the remote server. We can leave it to the
user to write TRUNCATE for foreign tables with the appropriate
options. If somebody complains about a problem that they will face
with this behavior, we can revisit.
That's one of the options. But I'm afraid it's hard to drop (revisit)
the feature once it has been released. So if there is no explicit
use case for that, basically I'd like to drop that before release
like we agree to drop unused TRUNCATE_REL_CONTEXT_CASCADING.
Thanks. Looks like the decision is going in the direction of
restricting those options, I will withdraw my point.
We are still discussing whether RESTRICT option should be pushed down to
a foreign data wrapper. But ISTM at least we could reach the consensus about
the drop of extra information for each foreign table. So what about applying
the attached patch and remove the extra information at first?
I'm fine with that direction. Thanks for the patch.
The change is straight-forward and looks fine, except the following
part.
==== contrib/postgres_fdw/sql/postgres_fdw.sql: 2436 -- after patching
2436> -- in case when remote table has inherited children
2437> CREATE TABLE tru_rtable0_child () INHERITS (tru_rtable0);
2438> INSERT INTO tru_rtable0 (SELECT x FROM generate_series(5,9) x);
2439> INSERT INTO tru_rtable0_child (SELECT x FROM generate_series(10,14) x);
2440> SELECT sum(id) FROM tru_ftable; -- 95
2441>
2442> TRUNCATE ONLY tru_ftable; -- truncate both parent and child
2443> SELECT count(*) FROM tru_ftable; -- 0
2444>
2445> INSERT INTO tru_rtable0 (SELECT x FROM generate_series(21,25) x);
2446> SELECT sum(id) FROM tru_ftable; -- 115
2447> TRUNCATE tru_ftable; -- truncate both of parent and
child
2448> SELECT count(*) FROM tru_ftable; -- 0
L2445-L2448 doesn't work as described since L2445 inserts tuples only
to the parent.
And there's a slight difference for no reason between the comment at
2442 and 2447.
Agreed. Thanks!
(The attached is a fix on top of the proposed patch.)
I will include this patch into the main patch.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
