Processing OODB queries by O-Algebra
Jie Lin, Zehra Meral Ozsoyoglu · 1996
O-Algebra is an object algebra designed for processing Object-Oriented Database (OODB) queries.We present the concept of internal type objects, which are uniform and represent the front-end objects.O-Algebra is an algebra whose operands are collections of internal objects.Due to uniform operands and simple operators defined in O-Algebra, a small yet powerful set of O-Algebra laws can be obtained, which is important for query optimization by algebraic rewriting.After presenting O-Algebra, we introduce an approach to transform OQL queries to O-Algebra queries.Since O-Algebra operations do not have complex arguments, the nested queries of OQL can be reduced by a general method after they are transformed t o O-Algebra queries.Compared to other approaches of reducing nested queries, this approach k more general because it is not restricted by the patterns of nested queries.