Combining Joins and Semijoins in Distributed Query Processing.

A new approach to distributed query processing is proposed. In the conventional approach, a query is processed by the reducing phase and the joining phase. In the reducing phase, the relations referenced in the query are reduced using semijoins, and all the relations are joined at the result site in the joining phase. In the proposed approach, an arbitrary interleaving of joins and semijoins is al…