Anthony Best <abest(at)digitalflex(dot)net> writes:
> I've noticed that the SUM() seems to overflow under some situations.
> The only difference is the order that the data is retrived from the
> database.
> accounting=# select sum(amount) from transactions, chart WHERE
> account=chart.id;
> sum
> ---------------------
> 5.6843418860808e-14
> (1 row)
> accounting=# select sum(amount) from transactions, chart WHERE
> account=chart.id AND amount=amount;
> sum
> -----
> 0
> (1 row)
That's not an overflow, it's merely roundoff error. If this surprises
you, possibly you should be using type NUMERIC instead of float.
regards, tom lane