Re: Windowing Function Patch Review -> Standard Conformance

From: "Hitoshi Harada" <umi(dot)tanuki(at)gmail(dot)com>
To: "Heikki Linnakangas" <heikki(dot)linnakangas(at)enterprisedb(dot)com>
Cc: "David Rowley" <dgrowley(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Windowing Function Patch Review -> Standard Conformance
Date: 2008-11-26 10:43:35
Message-ID: e08cc0400811260243q40332db1i61945bb96ccce7f8@mail.gmail.com
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2008/11/26 Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>:
> Hitoshi Harada wrote:
>>
>> 2008/11/26 David Rowley <dgrowley(at)gmail(dot)com>:
>>>
>>> I'm at a bit of a loss to what to do now. Should I wait for your work
>>> Heikki? Or continue validating this patch?
>>>
>>> The best thing I can think to do right now is continue and any problems I
>>> find you can add regression tests for, then if we keep your regression
>>> tests
>>> for Heikki's changes then we can validate those changes more quickly.
>>>
>>> Any thoughts? Better ideas?
>>
>> Thanks to your great tests, we now know much more about specification
>> and where to fail easily, so continuing makes sense but it may be good
>> time to take a rest and wait for Heikki's patch completing.
>
> Here's another updated patch, including all your bug fixes.
>
> There's two known issues:
> - ranking functions still don't treat peer rows correctly.
>
> - I commented out the "this function requires ORDER BY clause in the window"
> test in rank_up, because a window function shouldn't be poking into the
> WindowState struct like that. I wonder if it's really needed? In section
> 7.11, the SQL2008 spec says "if WD has no window ordering clause, then the
> window ordering is implementation-dependent, and *all rows are peers*". The
> regression test now fails because of this, but the current behavior actually
> seems correct to me.
>

Yes, I was wrong. The reason I put the error in rank() without ORDER
BY is nothing but I didn't find it. It is actually a reasonable
specification, isn't it.

This is tiny thing, but "negative transition function" can be called
"inverse transition function"? I feel the latter is more readable.

Regards,

--
Hitoshi Harada

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