VDict mobile



database An operational methodolgy, founded on predicatecalculus, dealing with descripitive expressions that are
equivalent to the operations of relational algebra. Codd'sreduction algorithm can convert from relational calculus to
Two forms of the relational calculus exist: the tuplecalculus and the domain calculus.
["An Introduction To Database Systems" (6th ed), C. J. Date,
Addison Wesley].
(1998-10-05)