Re: min,max aggregate functions
От | Oleg Bartunov |
---|---|
Тема | Re: min,max aggregate functions |
Дата | |
Msg-id | Pine.GSO.4.44.0202272048170.7901-100000@ra.sai.msu.su обсуждение исходный текст |
Ответ на | Re: min,max aggregate functions (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-hackers |
On Wed, 27 Feb 2002, Tom Lane wrote: > Oleg Bartunov <oleg@sai.msu.su> writes: > > AFAIK, it's required to write min(),max() aggregate functions for > > user-defined types even if compare function is already defined for > > this type. Is't possible to get these functions working for > > such user-defined types automatically ? > > Doesn't really seem worth the trouble. We'd need some sort of notion > of a generic aggregate function; and even then, you'd have to tell the > system what comparison function to use for your datatype. I was just curious. It's always possible to use 'order by desc limit 1' for max() function. So, nobody is working on aggregates. > > regards, tom lane > Regards, Oleg _____________________________________________________________ Oleg Bartunov, sci.researcher, hostmaster of AstroNet, Sternberg Astronomical Institute, Moscow University (Russia) Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/ phone: +007(095)939-16-83, +007(095)939-23-83
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