Re: POC: postgres_fdw insert batching

From: Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>
To: "Andrey V(dot) Lepikhov" <a(dot)lepikhov(at)postgrespro(dot)ru>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: POC: postgres_fdw insert batching
Date: 2020-07-12 00:11:01
Message-ID: 20200712001101.x65f3hvsanvamtgj@development
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

On Fri, Jul 10, 2020 at 09:28:44AM +0500, Andrey V. Lepikhov wrote:
>On 6/28/20 8:10 PM, Tomas Vondra wrote:
>>Now, the primary reason why the performance degrades like this is that
>>while FDW has batching for SELECT queries (i.e. we read larger chunks of
>>data from the cursors), we don't have that for INSERTs (or other DML).
>>Every time you insert a row, it has to go all the way down into the
>>partition synchronously.
>You added new fields into the PgFdwModifyState struct. Why you didn't
>reused ResultRelInfo::ri_CopyMultiInsertBuffer field and
>CopyMultiInsertBuffer machinery as storage for incoming tuples?

Because I was focused on speeding-up inserts, and that is not using
CopyMultiInsertBuffer I think. I agree the way the tuples are stored
may be improved, of course.


Tomas Vondra
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Jaka Jančar 2020-07-12 00:14:27 StartupMessage parameters - free-form or not?
Previous Message Peter Geoghegan 2020-07-12 00:08:31 Re: Default setting for enable_hashagg_disk