public inbox for [email protected]  

help / color / mirror / Atom feed

From: Gerardo Herzig <[email protected]>
To: Flávio Henrique <[email protected]>
Cc: [email protected]
Subject: Re: Slow query after 9.3 to 9.6 migration
Date: Tue, 27 Dec 2016 23:52:30 -0300 (ART)
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAOGex3nXTRPZTD-KeoSwD=bj62hQrMK+6h30u09srV71sePqUA@mail.gmail.com>
List-Unsubscribe:  <mailto:[email protected]?body=unsub%20pgsql-performance>

> 
> Hi there, fellow experts!
> 
> 
> I need an advice with query that became slower after 9.3 to 9.6
> migration.
> 
> 
> First of all, I'm from the dev team.
> 
> 
> Before migration, we (programmers) made some modifications on query
> bring it's average time from 8s to 2-3s.
> 
> 
> As this query is the most executed on our system (it builds the user
> panel to work), every bit that we can squeeze from it will be nice.
> 
> 
> Now, after server migration to 9.6 we're experiencing bad times with
> this query again.
> 
> 
> Unfortunately, I don't have the old query plain (9.3 version) to show
> you, but in the actual version (9.6) I can see some buffers written
> that tells me that something is wrong.
> 
> 
> Our server has 250GB of memory available, but the database team says
> that they can't do nothing to make this query better. I'm not sure,
> as some buffers are written on disk.
> 
> 
> Any tip/help will be much appreciated (even from the query side).
> 
> 
> Thank you!
> 
> 
> The query plan: https://explain.depesz.com/s/5KMn
> 
> 
> Note: I tried to add index on kilo_victor table already, but
> Postgresql still thinks that is better to do a seq scan.
> 
> 

I dont know about the data distribution in kilo_victor, but maybe a partial index
ON kilo_victor (juliet_romeo) where not xray_seven
?

Gerardo


-- 
Sent via pgsql-performance mailing list ([email protected])
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance

reply

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: [email protected]
  Cc: [email protected], [email protected]
  Subject: Re: Slow query after 9.3 to 9.6 migration
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox