Re: Aggregate Function (AVG) not calculated correctly - Mailing list pgsql-bugs

From Thomas Lockhart
Subject Re: Aggregate Function (AVG) not calculated correctly
Date
Msg-id 3A2D0E02.477B467C@alumni.caltech.edu
Whole thread Raw
In response to Aggregate Function (AVG) not calculated correctly  (pgsql-bugs@postgresql.org)
List pgsql-bugs
pgsql-bugs@postgresql.org wrote:
>
> Gavin Evans (gavin@consultant.com) reports a bug with a severity of 1
> The lower the number the more severe it is.
>
> Short Description
> Aggregate Function (AVG) not calculated correctly
>
> Long Description
> Using the following code:
> SELECT airline_code, AVG(distance) FROM flights GROUP BY airline_code;
>
> The first line of the result set (AI           | -2864) is calculated wrongly.
> I have included all code needed to prove the bug, this is a SERIOUS BUG!

You have not included all information required to understand the
problem. In particular, what is the schema? What version of PostgreSQL
are you using? What kind of machine?

Do you happen to be using int2 for the distance fields? In that case you
are likely (silently) overflowing your calculation.

Please post the schema and the data in such a way that we can read it
in! I'd suggest using pg_dump on the relevant table, but other
techniques can be used.

Regards.

                     - Thomas

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