From: Jesper Krogh <jesper@krogh.cc>
To: pgsql-performance@postgresql.org
Subject: Message queue table..
Date: Fri, 18 Apr 2008 19:49:39 +0200
Message-ID: <4808DF33.8000008@krogh.cc> (raw)
Hi.
I have this "message queue" table.. currently with 8m+ records. Picking
the top priority messages seem to take quite long.. it is just a matter
of searching the index.. (just as explain analyze tells me it does).
Can anyone digest further optimizations out of this output? (All records
have funcid=4)
# explain analyze SELECT job.jobid, job.funcid, job.arg, job.uniqkey,
job.insert_time, job.run_after, job.grabbed_until, job.priority,
job.coalesce FROM workqueue.job WHERE (job.funcid = 4) AND
(job.run_after <= 1208442668) AND (job.grabbed_until <= 1208442668) AND
(job.coalesce = 'Efam') ORDER BY funcid, priority ASC LIMIT 1
;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=0.00..0.09 rows=1 width=106) (actual
time=245.273..245.274 rows=1 loops=1)
-> Index Scan using workqueue_job_funcid_priority_idx on job
(cost=0.00..695291.80 rows=8049405 width=106) (actual
time=245.268..245.268 rows=1 loops=1)
Index Cond: (funcid = 4)
Filter: ((run_after <= 1208442668) AND (grabbed_until <=
1208442668) AND ("coalesce" = 'Efam'::text))
Total runtime: 245.330 ms
(5 rows)
--
Jesper
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: jesper@krogh.cc
Subject: Re: Message queue table..
In-Reply-To: <4808DF33.8000008@krogh.cc>
* 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