Re: ANTI-JOIN needs table, index scan not possible?

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От hans wulf
Тема Re: ANTI-JOIN needs table, index scan not possible?
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Msg-id 20110311175439.6380@gmx.net
обсуждение исходный текст
Ответ на Re: ANTI-JOIN needs table, index scan not possible?  (Maciek Sakrejda <msakrejda@truviso.com>)
Ответы Re: ANTI-JOIN needs table, index scan not possible?  (Kenneth Marshall <ktm@rice.edu>)
Список pgsql-performance
Thanks for the answer.

so there's no way around this problem? A nice index bitmap merge thing would be super fast. Big table ANTI JOIN queries
withonly a few results expected, are totally broken, if this is true.  

This way the query breaks my neck. This is a massive downside of postgres which makes this kind of query impossible.
Mysqlgives you the answer in a few seconds :-( 



> Possibly because the index entries you're anti-joining against may
> point to deleted tuples, so you would erroneously omit rows from the
> join result if you skip the visibility check?
>
> ---
> Maciek Sakrejda | System Architect | Truviso
>
> 1065 E. Hillsdale Blvd., Suite 215
> Foster City, CA 94404
> (650) 242-3500 Main
> www.truviso.com

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