in this paper we define ?-independent (a weak-version of independence), kronecker and dissociate sets on hypergroups and study their properties and relationships among them and some other thin sets such as independent and sidon sets. these sets have the lacunarity or thinness property and are very useful indeed. for example varopoulos used the kronecker sets to prove the malliavin theorem. in t...

Spatial joins are fundamental in spatial databases. Over the last decade, the primary focus of research has been on joins with the predicate “region intersection.” In modern database applications involving geospatial data such as GIS, efficient evaluation of joins with other spatial predicates is yet to be fully explored. In addition, most existing join algorithms were developed for two-way joi...

Abstract The aim of this work was to develop a technique speed up complex joins in an incremental visual query system. When designing visual, highly interactive interface for ad-hoc (read-only) queries, fast response times are paramount importance. While column-oriented DBMS reduces the inherent latency found relational DBMS, there is still question how index data, especially so as support join...