From: twoflower <standa.kurik@gmail.com>
To: pgsql-performance@postgresql.org
Subject: Re: Huge difference between ASC and DESC ordering
Date: Mon, 6 Mar 2017 09:46:32 -0700 (MST)
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Thank you Jeff.
There are 7 million rows satisfying fk_id_client = 20045. There is an index
on fk_id_client, now I added a composite (fk_id_client, id) index but that
did not help.
I see the point of what you are saying, but still don't understand how these
two situations (*asc* vs. *desc*) are not symmetrical. I mean, there /is/ an
ascending index on *JOB_MEMORY.id*, so why does it matter which end I am
picking the data from?
The thing is, even when I force Postgres to use the ascending index on *id*,
it's still orders of magnitude slower than the *desc* version (even when
that one goes through the index backwards).
--
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To: pgsql-performance@postgresql.org
Cc: standa.kurik@gmail.com
Subject: Re: Huge difference between ASC and DESC ordering
In-Reply-To: <1488818792254-5947737.post@n3.nabble.com>
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