Re: pgsql/src/backend/nodes (copyfuncs.c outfuncs.c print.c) - Mailing list pgsql-committers

From Hiroshi Inoue
Subject Re: pgsql/src/backend/nodes (copyfuncs.c outfuncs.c print.c)
Date
Msg-id 39F8D0A4.A9A22EE1@tpf.co.jp
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In response to pgsql/src/backend/nodes (copyfuncs.c outfuncs.c print.c)  (Tom Lane <tgl@postgresql.org>)
Responses Re: pgsql/src/backend/nodes (copyfuncs.c outfuncs.c print.c)  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: pgsql/src/backend/nodes (copyfuncs.c outfuncs.c print.c)  (Tom Lane <tgl@sss.pgh.pa.us>)
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Tom Lane wrote:

> Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > It seems to me that LIMIT in declare cursor statement is only
> > for optimizer's hint.
>
> I think that would just confuse people.

It could be. However what does LIMIT mean ?
Rows per FETCH ? Probably no.
FETCH forward,backward,forward,backward,.... and suddenly EOF ?

> If we want to have a hint
> that says "optimize for fast start", it ought to be done in another
> way than saying that SELECT ... LIMIT means different things in
> different contexts.
>

Yes I want to give optimizer a hint  "return first rows fast".
When Jan implemented LIMIT first,there was an option
"LIMIT ALL" and it was exactly designed for the purpose.

Regards.
Hiroshi Inoue


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