I posted the questions below a few days ago to the SQL list, but
apparently there is nobody there who can help -- maybe I'm luckier in
this list? :-)
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I'm a novice to postgresql, so please excuse me if I'm addressing to
the wrong mailing list!
I need to specify some column functions for statistical analysis,
e.g. standard deviation or variance. After reading the user's guide I
think that's to realize with aggregates, but with those docs only I
cannot figure out how to do it -- does anybody know whether there is a
ready-for-use "statistics" package, or how to write something that's
usable in a SQL statement like this:
select date, avg(temperature), stddev(temperature)
from temperatures
where date between '01.01.1999' and '15.02.1999'
group by date ?
Other question: I'm used to use DB2/2, and DB2/2 has functions like
"month(some_date)" and "hour(some_timestamp)". Are there equivalents
in postgresql?
Many thanks in advance for help + patience!
Ulf
--
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%%%%% Ulf Mehlig <ulf.mehlig@uni-bremen.de>
%%%%!%%% Projekt "MADAM" <umehlig@uni-bremen.de>
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