Re: TODO Item: IN(long list ...)

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От Tom Lane
Тема Re: TODO Item: IN(long list ...)
Дата
Msg-id 8843.1162328851@sss.pgh.pa.us
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Ответ на Re: TODO Item: IN(long list ...)  (Alvaro Herrera <alvherre@commandprompt.com>)
Ответы Re: TODO Item: IN(long list ...)  (Josh Berkus <josh@agliodbs.com>)
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Alvaro Herrera <alvherre@commandprompt.com> writes:
> Josh Berkus wrote:
>> -- Improve performance of queries with IN() clauses containing hundreds or 
>> more literal values, possibly by re-writing it as a join to a virtual 
>> table.

> Hmm, wasn't there some work on this regard in 8.2?

I think it's pretty much done.  Try WHERE foo IN (VALUES (1),(2),...)
if you have so many values that a non-nestloop join seems indicated.
The plain non-VALUES list form is also significantly faster than it
was, but I think it will only result in a bitmap indexscan plan type.
        regards, tom lane


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