188 страниц. 2010 год. LAP Lambert Academic Publishing In this book we present original algorithms used to obtain aggregated values sets from relational database. We introduce some notations that help us to specify sets of aggregation types and we present three algorithms. In order to highlight the applicability of these algorithms, in the last chapter we present a study on holiday rates in Romanian Black Sea resorts. The algorithms are implemented in the Borland Delphi programming environment using Microsoft Office Access databases.