EXTENDED RELATIONAL ALGEBRA FOR REDUCTION OF NATURAL QUANTIFIER COOL EXPRESSIONS
Date
1994-05-01
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Abstract
An extended relational algebra has been developed. This extended
algebra is suitable for reduction of expressions written in the
object-oriented natural quantifier language COOL. The algebra consists
of conventional operations plus a group select, a subgroup select and
possibility join operation. The group select operation selects each
group of related tuples where a quantity of the group obeys a condition.
The subgroup select operation selects each group of related tuples where
a quantity of a subgroup of the group obeys a condition. The possibility
join of relation R1 with relation R2 regenerates relation R1 but with each
tuple having a logical attribute p concatenated, with p true where the R1
tupple could have been joined to an R2 tuple, otherwise p false.
Generalized algebra routines for generalized COOL expressions are presented.
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Computer Science