From: Hiroshi Inoue <Inoue@tpf.co.jp>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: pgsql-hackers@postgresql.org
Subject: Re: MOVE LAST: why?
Date: Wed, 08 Jan 2003 18:31:42 +0900
Message-ID: <3E1BEFFE.88B57516@tpf.co.jp> (raw)
References: <200301072329.h07NT2X28922@candle.pha.pa.us>
<27934.1041984327@sss.pgh.pa.us>
<3E1B9DCD.75859501@tpf.co.jp>
<501.1041997832@sss.pgh.pa.us>
<3E1BA5E6.9463718F@tpf.co.jp>
<863.1042000401@sss.pgh.pa.us>
<3E1BAFF6.B0114A67@tpf.co.jp>
<1082.1042002375@sss.pgh.pa.us>
Tom Lane wrote:
>
> Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > FETCH LAST should return the last one row.
>
> That's not clear to me. Generally, I would think the cursor should
> remain positioned on whatever row is returned, but the spec clearly says
> that the final cursor position after FETCH LAST is *after* the last row.
In SQL99 the spec you referred to seems the ii) of b) which
begins with the word *Otherwise*. I see the following before it.
a) If K is greater than 0 (zero) and not greater than N, then CR
is positioned on the K-th row of Tt and the corresponding row
of T. That row becomes the current row of CR.
Then I'm also suspicious if MOVE LAST should mean MOVE ALL.
> > FETCH RELATIVE m should return a row after skipping
> > m rows if we follow the SQL standard and so the current
> > implementation of FETCH RELATIVE is broken.
>
> No objection to that here. Are you volunteering to make it do that?
I'm suspicios if we should implement scrollable cursors
with the combination of the current MOVE and FETCH implemen-
tation. For example the backwards FETCH operation for group
nodes isn't implemented properly yet(maybe). Should we fix
it or take another way ?
regards,
Hiroshi Inoue
http://w2422.nsk.ne.jp/~inoue/
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Cc: Inoue@tpf.co.jp, tgl@sss.pgh.pa.us, pgman@candle.pha.pa.us, pgsql-hackers@postgresql.org
Subject: Re: MOVE LAST: why?
In-Reply-To: <3E1BEFFE.88B57516@tpf.co.jp>
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