Re: Tuning a query with ORDER BY and LIMIT

On Wed, Jun 22, 2022 at 3:39 PM Dirschel, Steve <
steve(dot)dirschel(at)thomsonreuters(dot)com> wrote:

> explain (analyze, verbose, costs, buffers, timing, summary, hashes)
>

'hashes', what's that? Are you using community PostgreSQL, or someones
fork?

> With Oracle for a query like this since the index is on the 3 columns
> matching the WHERE clause and the ORDER BY clause is in the 4th position
> Oracle would be able to scan that index and as soon as it finds the first
> matching 50 rows.
>

Can you show the plan from Oracle? I'm not an expert at reading their
plans, but certainly they are easier to attempt to read if you can at least
see them.

> I was questioning if the result IN clause was causing the issue so I ran
> the query with result = and see the same results:
>
>
I can't reproduce this at all. With simple equality it absolutely uses the
index for ordering in that case, even in v10.

Cheers,

Jeff

>