(2018/08/21 16:03), Amit Langote wrote:
On 2018/08/20 23:43, Tom Lane wrote:
Chris Travers<chris.trav...@adjust.com> writes:
I am looking at trying to make two modifications to the PostgreSQL FDW and
would like feedback on this before I do.
1. INSERTMETHOD=[insert|copy] option on foreign table.
One significant limitation of the PostgreSQL FDW is that it does a prepared
statement insert on each row written which imposes a per-row latency. This
hits environments where there is significant latency or few latency
guarantees particularly hard, for example, writing to a foreign table that
might be physically located on another continent. The idea is that
INSERTMETHOD would default to insert and therefore have no changes but
where needed people could specify COPY which would stream the data out.
Updates would still be unaffected.
A different thing we could think about is enabling COPY TO/FROM a
foreign table.
Fwiw, the following commit did introduce COPY FROM support for foreign
tables, although using a FDW INSERT interface, so not exactly optimized
for bulk-loading yet.
commit 3d956d9562aa4811b5eaaaf5314d361c61be2ae0
Author: Robert Haas<rh...@postgresql.org>
Date: Fri Apr 6 19:16:11 2018 -0400
Allow insert and update tuple routing and COPY for foreign tables.
That's right. To improve the efficiency, I plan to work on COPY FROM/TO
a foreign table for PG12 (In [1], I proposed new FDW APIs for COPY FROM).
Sorry, I'm late to the party.
Best regards,
Etsuro Fujita
[1]
https://www.postgresql.org/message-id/23990375-45a6-5823-b0aa-a6a7a6a957f0%40lab.ntt.co.jp
