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Home -> Community -> Usenet -> comp.databases.theory -> Re: Nested Sets vs. Nested Intervals
Mneson is not Codasyl nor OQL based on the descriptions I have of
those.
I believe the Mneson Calculus is an algebra. I'm still working on it. Example laws:
T ({x1, x2, ...}) = T({x1}) U T({x2}) U ...
T ({}) = {}
T (XUY) = T(X) U T(Y)
T (X^Y) = T(X) ^ T(Y)
Conditions on values are made possible by introducing value ranges, set of values expressed in a compact way, typically as an interval or a bound. Querying for employees earning less than 40,000:
T (Employees) ^ S (S (T (T (Salary)) ^ RangeForLessThan (40'000)))
Of course query optimization would kick in here, and that's the main purpose of having the algebra. Received on Thu Nov 10 2005 - 21:02:24 CST
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