Re: PostgreSQL as a local in-memory cache - Mailing list pgsql-performance

From Greg Smith
Subject Re: PostgreSQL as a local in-memory cache
Date
Msg-id 4C188AD4.20209@2ndquadrant.com
Whole thread Raw
In response to Re: PostgreSQL as a local in-memory cache  ("jgardner@jonathangardner.net" <jgardner@jonathangardner.net>)
Responses Re: PostgreSQL as a local in-memory cache  ("Pierre C" <lists@peufeu.com>)
Re: PostgreSQL as a local in-memory cache  (Jonathan Gardner <jgardner@jonathangardner.net>)
List pgsql-performance
jgardner@jonathangardner.net wrote:
> NOTE: If I do one giant commit instead of lots of littler ones, I get
> much better speeds for the slower cases, but I never exceed 5,500
> which appears to be some kind of wall I can't break through.
>

That's usually about where I run into the upper limit on how many
statements Python can execute against the database per second.  Between
that and the GIL preventing better multi-core use, once you pull the
disk out and get CPU bound it's hard to use Python for load testing of
small statements and bottleneck anywhere except in Python itself.

I normally just write little performance test cases in the pgbench
scripting language, then I get multiple clients and (in 9.0) multiple
driver threads all for free.

--
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us


pgsql-performance by date:

Previous
From: "Pierre C"
Date:
Subject: Re: PostgreSQL as a local in-memory cache
Next
From: David Jarvis
Date:
Subject: Re: Analysis Function