>
> I still think one shouldn't allow NULL values in unique constraints
> unless it's the _only_ value (any value is unique if there are no other
> values to compare with, after all), but I can't compare myself to
> C.Date, Darwen or Tom Lane... I'm not a database deity :P
You can not declare a unique value on nothing... thus the reasoning :)
>
> I suspect they have some pretty good reasons to treat NULL values in a
> UNIQUE constraint as different even from other NULL values. It sure
> makes me curious though ;)
>
> Regards,
>
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