Re: optimizing query with multiple aggregates - Mailing list pgsql-performance

From David Wilson
Subject Re: optimizing query with multiple aggregates
Date
Msg-id e7f9235d0910211947h5eedf6behc586156e79709160@mail.gmail.com
Whole thread Raw
In response to optimizing query with multiple aggregates  (Doug Cole <dougcole@gmail.com>)
List pgsql-performance


On Wed, Oct 21, 2009 at 6:51 PM, Doug Cole <dougcole@gmail.com> wrote:

repeated across many different x,y values and fields to build out several histograms of the data.  The main culprit appears to be the CASE statement, but I'm not sure what to use instead.  I'm sure other people have had similar queries and I was wondering what methods they used to build out data like this?

Use group by with an appropriate division/rounding to create the appropriate buckets, if they're all the same size.

select round(field/100) as bucket, count(*) as cnt from foo group by round(field/100);

--
- David T. Wilson
david.t.wilson@gmail.com

pgsql-performance by date:

Previous
From: Doug Cole
Date:
Subject: Re: optimizing query with multiple aggregates
Next
From: Nikolas Everett
Date:
Subject: Re: optimizing query with multiple aggregates