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Re: Frames vs partitions: is SQL2008 completely insane?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: pgsql-hackers(at)postgreSQL(dot)org, Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com>
Subject: Re: Frames vs partitions: is SQL2008 completely insane?
Date: 2008-12-26 21:41:01
Message-ID: 15681.1230327661@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackers
I wrote:
> Lastly, for a simple aggregate used with an OVER clause, the current
> patch seems to define the aggregate as being taken over the frame
> rather than the partition, but I cannot find anything in SQL2008 that
> lends any support to *either* definition.

Never mind that --- I found it in 10.9 syntax rule 4.b.

But what this seems to boil down to is that LEAD() and LAST_VALUE()
are completely useless unless you're allowed to specify a nondefault
framing clause ... and don't mind ignoring the clearly-insane
restriction of 6.10 syntax rule 6.b.

The minimum extra functionality needed to make these functions useful
would seem to be to allow UNBOUNDED FOLLOWING ...

			regards, tom lane

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