On 09/03/10 13:35 +0100, Cédric Krier wrote: > Here is a patch to fix digits issue in product uom due to new validation of > digits. > > Please review this at http://codereview.appspot.com/325042/show >
I'm facing an issue.
The float8 of postgresql can not store correctly the value:
1.093613298338
It is rounded to:
1.09361329834
This value comes from the Yard UOM which is:
1 yard = 0.9144 meters
So:
1 meter = round(1.0 / 0.9144, 12) meters = 1.093613298338
The issue is that when trying to compute back the 0.9144 with the rounded
value we get:
round(1.0 / 1.09361329834, 12) = 0.914399999998
But with the 12 digits value:
round(1.0 / 1.093613298338, 12) = 0.9144
So float8 is not large enough to store the Yard conversion correctly. I
propose to store rate and factor with numeric/decimal field instead of float.
The precision has no limit but it will require to convert into float when
calling compute_qty(). This function is called in the stock module to compute
stock quantity, it is already well optimized to reduce the number of call but
it will be a little slower due to the convertion of Decimal into float but I
don't think we should care about.
So if there is no objection, I will complete the patch with this change.
--
Cédric Krier
B2CK SPRL
Rue de Rotterdam, 4
4000 Liège
Belgium
Tel: +32 472 54 46 59
Email/Jabber: [email protected]
Website: http://www.b2ck.com/
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