Affiliation:
1. University of Louisville, USA
Abstract
Set-oriented queries are those that require a condition to hold of an arbitrary set of rows, either when comparing the set to a single row or to another set of rows. Examples of such queries are universally quantified queries and skyline queries. These queries, while important for data processing, are difficult to write and difficult to process. In this chapter we review research dealing with the specification and optimization of such queries. We present several approaches proposed to deal with universal quantification as well as with set predicates in general.