number of rows in analyze

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От Willy-Bas Loos
Тема number of rows in analyze
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Msg-id CAHnozTj5o7vJ3bJ_V0KUAA5dEopxpnE3akkew8pyurGy+cEf_Q@mail.gmail.com
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Ответы Re: number of rows in analyze
Re: number of rows in analyze
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Hi,

I'ver been wondering how to set the number of rows that are scanned by
analyze. (I want to increase it)
I couln't find it at first but when i read closer i found that is does:
"The largest statistics target among the columns being analyzed
determines the number of table rows sampled to prepare the
statistics."
(http://www.postgresql.org/docs/8.4/interactive/sql-analyze.html)


My question is *HOW* does it "detirmine the number of table rows
sampled" with the statistics target?
What is the formula behind it?

I am not familiar enough with the source code to figure that out
myself. sry about that.
Would be good to include in the docs if we find out.

Cheers,

WBL

--
"Patriotism is the conviction that your country is superior to all
others because you were born in it." -- George Bernard Shaw

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