From: Pujol Mathieu <mathieu.pujol@realfusio.com>
To: pgsql-performance@postgresql.org
Subject: GIST optimization to limit calls to operator on sub nodes
Date: Mon, 23 Jun 2014 09:20:39 +0200
Message-ID: <53A7D547.5080302@realfusio.com> (raw)
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>
Hello,
I already post my question in the General Mailing list, but without
succeed so I try this one that seems to me more specialized.
My question is about GIST index.
I made my own index to handle specific data and operators. It works
pretty fine but I wonder if it was possible to optimize it.
When I run my operator on a GIST node (in the method
gist_range_consistent) it returns "NotConsistent" / "MaybeConsistent" /
"FullyConsistent".
NotConsistent -> means that all subnodes could be ignored,
gist_range_consistent return false
MaybeConsistent -> means that at least one subnode/leaf will be
consistent, gist_range_consistent return true
FullyConsistent -> means that all subnodes/leaves will be consistent,
gist_range_consistent return true
So like with the "recheck flag" I would like to know if there is a way
to notify postgres that it is not necessary to rerun my operator on
subnodes, to speedup the search.
For example, consider the following gist tree
R
/ \
Na Nb
/ \ / \
La1 La2 Lb1 Lb2
If all nodes return FullyConsistent, postgres will run tests in that
Order : R, Na, Nb, La1, La2, Lb1, Lb2, thanks to recheck flag it will
not test rows associated to leaves Lxx.
My goal is that postgres run test on R and then skip tests on other
nodes. So is there a way to do that in the GIST API ? Or could I share
data from R to Nx and then From Na to Lax and Nb to Lbx ?
Thanks,
Mathieu
--
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: mathieu.pujol@realfusio.com
Subject: Re: GIST optimization to limit calls to operator on sub nodes
In-Reply-To: <53A7D547.5080302@realfusio.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox