The powerset algebra as a natural tool to handle nested database relations

The Powerset Algebra as a Natural Tool to Handle Nested Database Relations

The nested relational algebra is often inadequate as a tool to handle nested relations, since several important queries, such as transitive closure, cannot expressed by it. On the other hand, the powerset algebra does allow the expression of transitive closure, but in a too expensive way. Therefore, we consider various other extensions to the nested algebra, such as least tixpoint and programmi...

A temporal database model using nested relations

................................................................................................................................................................3 ACKNOWLEDGMENTS ......................................................................................................................................10

Simulation of the nested relational algebra by the flat relational algebra, with an application to the complexity of evaluating powerset algebra expressions

Paredaens and Van Gucht proved that the at relational algebra has the same expressive power as the nested relational algebra as far as queries over at relations and with at results are concerned We provide a new very direct proof of this fact using a simulation technique Our technique is also applied to partially answer a question posed by Suciu and Paredaens regarding the complexity of evaluat...

Simulation of the Nested Relational Algebra by the at Relational Algebra, with an Application to the Complexity of Evaluating Powerset Algebra Expressions

Paredaens and Van Gucht proved that the at relational algebra has the same expressive power as the nested relational algebra, as far as queries over at relations and with at results are concerned. We provide a new, very direct proof of this fact using a simulation technique. Our technique is also applied to partially answer a question posed by Suciu and Paredaens regarding the complexity of eva...

An Extension of an Algebra for Nested Relations