[HN Gopher] A Query Language Is Also a Data Constraint Language
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       A Query Language Is Also a Data Constraint Language
        
       Author : nchammas
       Score  : 13 points
       Date   : 2021-10-31 16:27 UTC (6 hours ago)
        
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       | contravariant wrote:
       | Mathematically it's somewhat obvious that constraining the set of
       | allowed relations is equivalent to defining a function from a
       | relation to {true,false}. So I suppose it isn't too surprising
       | that queries are equivalent to constraints.
       | 
       | That said for this most general definition for a relation over
       | set X1, X2, ..., Xn the number of relations is 2^(X1 X2 ... Xn)
       | so the number of constraints is even more ridiculous and would
       | require at least 2^(X1 X2 ... Xn) bits to just enumerate them
       | all, so it's pretty obvious that there can only be a small subset
       | of constraints that can be represented efficiently.
        
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       (page generated 2021-10-31 23:01 UTC)