Thread: Bug in optimizer

Bug in optimizer

From
Timo Nentwig
Date:
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Hi!

Your bug report form on the web doesn't work.


This is very slow:

SELECT urls.id FROM urls WHERE
(
    urls.id <> ALL (SELECT html.urlid FROM html)
);

...while this is quite fast:

SELECT urls.id FROM urls WHERE
(
    NOT (EXISTS (SELECT html.urlid FROM tml WHERE
    (
        html.urlid = urls.id
    )))
);

Regards
Timo
- --
http://nentwig.biz/ (J2EE)
http://nitwit.de/

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Re: Bug in optimizer

From
Gaetano Mendola
Date:
Timo Nentwig wrote:

> This is very slow:
>
> SELECT urls.id FROM urls WHERE
> (
>     urls.id <> ALL (SELECT html.urlid FROM html)
> );
>
> ...while this is quite fast:
>
> SELECT urls.id FROM urls WHERE
> (
>     NOT (EXISTS (SELECT html.urlid FROM tml WHERE
>     (
>         html.urlid = urls.id
>     )))
> );

Are you using the version 7.4.x ?



Regards
Gaetano Mendola