Re: Do we need multiple forms of the SQL2003 statistics

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От Peter Eisentraut
Тема Re: Do we need multiple forms of the SQL2003 statistics
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Msg-id 200607292107.04152.peter_e@gmx.net
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Ответ на Re: Do we need multiple forms of the SQL2003 statistics  ("Sergey E. Koposov" <math@sai.msu.ru>)
Ответы Re: Do we need multiple forms of the SQL2003 statistics  ("Sergey E. Koposov" <math@sai.msu.ru>)
Re: Do we need multiple forms of the SQL2003 statistics  (Tom Lane <tgl@sss.pgh.pa.us>)
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Sergey E. Koposov wrote:
> I think since we are supporting the numeric type as a special
> high-precision type, Postgres must have the high-precision
> versions of all computational functions. Just my opinion.

Another way to look at it is whether you want to have accurate 
computations (numeric) or approximate computations (float).  I'm not a 
statistician, so I don't know what most of these functions are used 
for.  From a mathematician's point of view, however, some of these 
functions normally produce irrational numbers anyway, so it seems 
unlikely that numeric will be useful.  But looking at the definition 
of, say, regr_avgx(Y, X), if all the input values are integers, it 
might be useful if I could get an exact integer or rational number as 
output, instead of a float, that is.

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/


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