Re: FW: query optimization question

From: Richard Huxton <dev(at)archonet(dot)com>
To: <terry(at)ashtonwoodshomes(dot)com>, "Postgresql Sql Group (E-mail)" <pgsql-sql(at)postgresql(dot)org>
Subject: Re: FW: query optimization question
Date: 2002-11-06 15:11:22
Message-ID: 200211061511.22676.dev@archonet.com
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On Wednesday 06 Nov 2002 2:01 pm, terry(at)ashtonwoodshomes(dot)com wrote:

> However, for the total deficiencies I am then splitting up the total into
> aging groups, eg <30, 30-60, 60-90, and >90 days old. The query for that
> looks like the below. But before I paste it in, I would like to optimize
> it, if I could do so with a group by clause I most certainly would, but I
> don't see how I can BECAUSE OF THE AGING BREAKDOWN:

[one sub-query per age-range]
> AND dt.days_old_start_date < {d '2002-10-07'}

> ) AS def_count_less_30,

> AND dt.days_old_start_date >= {d '2002-10-07'}
> AND dt.days_old_start_date < {d '2002-09-07'}

> ) AS def_count_30_60,

Could you not define a function age_range(date) to return the relevant range
text, then group on that text? I've used that before.

--
Richard Huxton

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