Re: meaning of default_statistics_target

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От Alvaro Herrera
Тема Re: meaning of default_statistics_target
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Msg-id 20080428145739.GA5761@alvh.no-ip.org
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Ответ на Re: meaning of default_statistics_target  (Martin Marques <martin@marquesminen.com.ar>)
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Martin Marques escribió:

> Is the value measured in some scale, or does it depend on something
> internal? What does 1000 mean?

1000 histogram and MCV entries, and also a larger sample:

>> Increasing the target also increases the number of rows that ANALYZE
>> samples to prepare the stats, so you should theoretically get more
>> accurate stats for the other columns too, even though they'll still get
>> boiled down to the same array lengths as before.

How larger is the sample, I don't know.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

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