Re: Speeding up Aggregates - Mailing list pgsql-performance

From Greg Stark
Subject Re: Speeding up Aggregates
Date
Msg-id 874qyh8zoo.fsf@stark.dyndns.tv
Whole thread Raw
In response to Re: Speeding up Aggregates  (Dror Matalon <dror@zapatec.com>)
Responses Re: Speeding up Aggregates  (Christopher Kings-Lynne <chriskl@familyhealth.com.au>)
Re: Speeding up Aggregates  (Rob Nagler <nagler@bivio.biz>)
List pgsql-performance
Dror Matalon <dror@zapatec.com> writes:

> Ouch. I just double checked and you're right. Is this considered a bug,
> or just an implementation issue?

Call it a wishlist bug. The problem is it would be a hard feature to implement
properly. And none of the people paid to work on postgres by various companies
seem to have this on their to-do lists. So don't expect it in the near future.

> While I've seen this hint a few times in the lists, it seems like it's
> one of those magic incantations that those in the know, know about, and
> that people new to postgres are going to be surprised by the need to use
> this idiom.

Yup. Though it's in the FAQ and comes up on the mailing list about once a week
or so, so it's hard to see how to document it any better. Perhaps a warning
specifically on the min/max functions in the documentation?


Say, what do people think about a comment board thing like php.net has
attached to the documentation. People can add comments that show up directly
on the bottom of the documentation for each function. I find it's mostly full
of junk but skimming the comments often turns up one or two relevant warnings,
especially when I'm wondering why something's not behaving the way I expect.

--
greg

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