Re: [HACKERS] Re: Subselects open issue Nr. NEW

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От Michael Hirohama
Тема Re: [HACKERS] Re: Subselects open issue Nr. NEW
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Msg-id l03110740b10ebbe12b36@[204.179.134.140]
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Ответ на Re: Subselects open issue Nr. NEW  ("Vadim B. Mikheev" <vadim@sable.krasnoyarsk.su>)
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At 10:31 +0700 2/17/98, Vadim B. Mikheev wrote:
[...]
>
>I understand this. And this is how it works currently:
>
>select * from tab where (A,B) >= ANY (select X, Y from tab2);
>
>means: select tuples where A >= X _and_ B >= Y for some tuple from tab2.
>                                  ^^^^^
>         'AND' is used for all Op-s except for '<>' when 'OR' is used.
>
>Question is "should we drop this feature (?) or leave it as is ?"
>
>Comments ?
>
>Vadim

I recommend dropping this feature and only supporing =ANY and <>ANY.
Supporing the relational operators cannot be optimized in the general case.

If I needed to perform the <=ANY query efficiently, I might use a
functional index on 'A' and 'B' using an R-tree method.

Regards,

--
Michael Hirohama <kamesan@ricochet.net>



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