Horton

Re: ORDER BY pushdowns seem broken in postgres_fdw

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Ronan Dunklau <ronan.dunklau@aiven.io>
Cc: Robert Haas <robertmhaas@gmail.com>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Ranier Vilela <ranier.vf@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2021-07-27T06:05:19Z
Lists: pgsql-hackers 
On Tue, 27 Jul 2021 at 17:20, Ronan Dunklau <ronan.dunklau@aiven.io> wrote:
> One thing in particular I was not sure about was how to fetch the operator
> associated with the path key ordering. I chose to go through the opfamily
> recorded on the member, but maybe locating the original SortGroupClause by its
> ref and getting the operator number here woud have worked. It seems more
> straightforward like this though.

I spent a bit of time trying to find a less invasive way of doing that
and didn't manage to come up with anything. I'm interested to hear if
anyone else has any better ideas.

David

Commits

  1. Fix postgres_fdw to check shippability of sort clauses properly.

  2. postgres_fdw: Add ORDER BY to some remote SQL queries.