From: Joseph Syjuco <joseph@asti.dost.gov.ph>
To: postgres <pgsql-sql@postgresql.org>
Subject: variance aggregate function incorrect? Reference Materials reg create aggregate
Date: 24 Jun 2002 18:13:25 -0400
Message-ID: <1024956806.2590.22.camel@Askr> (raw)
hi
i needed the variance function ... i dont know if i introduced the wrong
parameters or maybe this variance is not the variance that im looking
for but it doesnt provide the right results
variance=(nEx^2 - (Ex)^2)/(n(n-1))
my sql statement
select variance(answer) from tbl_answer (where answer is of type
integer)
because of this i need to create my own variance aggregate (unless
someone enlightens me on whats happening with the variance aggregate) so
i would like to know if theres anyone who knows a good create aggregate
tutorial (with samples) ... all i got from google so far is the
reference from ninthwonder.com
TIA
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To: pgsql-sql@postgresql.org
Cc: joseph@asti.dost.gov.ph
Subject: Re: variance aggregate function incorrect? Reference Materials reg create aggregate
In-Reply-To: <1024956806.2590.22.camel@Askr>
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