Martijn van Oosterhout wrote:
> On Tue, Jan 25, 2005 at 10:40:15AM +0100, Pailloncy Jean-Gerard wrote:
>>This "extended type" was wonderful, because there was warning/error if
>>"extend type" does not match in any computation: you can not add apple
>>to orange.
>
>
> I think it's a wonderful idea. You could use a similar mechanism to
> implement:
>
> - Currencies (so you can't add dollars to pounds)
> - Timezone aware timestamps (so a time in Australia looks differet from
> a time in Europe)
>
> Probably much more.
Indeed, you could even add a way to convert between different types if
they are in the same categories; for example convert between dollars and
euro's or between degrees Celsius and degrees Fahrenheit (that's a
trickier one, the shell command 'units' returns wrong results there).
Of course, it's still not possible to add dollars and degrees
Fahrenheit... (hence the category concept I mentioned)
You could even determine that if you divide a quantity in meters by a
quantity in seconds that you're talking about a speed... I think there
are quite a few people on this planet who would be happy about that.
OTOH, it's probably not that a good idea to add all kinds of complicated
(read: "processor intensive") math to a database engine.
Just my 0.02 Euro.
--
Regards,
Alban Hertroys
MAG Productions
P: +31(0)53 4346874
F: +31(0)53 4346876
E: alban@magproductions.nl
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