Re: Highly Efficient Custom Sorting

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
Cc: Eliot Gable <egable+pgsql-performance(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Highly Efficient Custom Sorting
Date: 2010-07-02 04:08:50
Message-ID: 4767.1278043730@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Craig Ringer <craig(at)postnewspapers(dot)com(dot)au> writes:
> On 02/07/10 08:46, Eliot Gable wrote:
>> So, the bottom line is, I need a faster way to do this sorting.

> You haven't showed us how you're doing it at the moment, so it's awfully
> hard to comment usefully on possible approaches.

I'm guessing from tea leaves, but the impression I got from Eliot's
description is that he's using plpgsql functions as sort comparators.
It's not surprising that that sucks performance-wise compared to having
the equivalent logic in C/C++ functions used as comparators on the
client side. plpgsql is no speed demon. Best fix might be to code the
comparators as C functions on the server side.

regards, tom lane

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Michal Fapso 2010-07-02 05:23:21 Re: big data - slow select (speech search)
Previous Message Tom Lane 2010-07-02 04:05:04 Re: No hash join across partitioned tables?