We address the issue of designing eeective query languages for OLAP databases. The basis of our investigation is MD, a logical data model for multidimensional databases that, unlike other multidimensional models, is independent of any speciic implementation. As such, MD provides a clear separation between practical and conceptual aspects of multidimen-sional analysis. In this framework, we pres...

The indexing techniques in multidimensional databases are becoming more and more important. The data warehouse environment has become a popular technology and a lot of research work has been done in order to improve the query performance and to provide faster response times. The ability to answer these queries e fficiently is a critical issue since most of them are complex and iterative. In thi...

The class of !-languages recognized by systolic (binary) tree automata is introduced. That class extends the class of B uchi !-languages though maintaining the closure under union, intersection and complement and the decidability of emptiness. The class of systolic tree !-languages is characterized in terms of a (suitable) concatenation of ((nitary) systolic tree languages. A generalization of ...

Fuzzy rule-based systems have been very popular in many engineering applications. In mineral engineering, fuzzy rules are normally constructed using some fuzzy rule extraction techniques to establish the determination model in predicting the d50c of hydrocyclones. However, when generating fuzzy rules from the available information, it may result in a sparse fuzzy rule base. The use of more than...

Multidimensional similarity join finds pairs of multidimensional points that are within some small distance of each other. The -k-d-B tree has been proposed as a data structure that scales better as the number of dimensions increases compared to previous data structures. We present a cost model of the -k-d-B tree and use it to optimize the leaf

Indexing methods for efficient processing of multidimensional data are very requested in many fields, like geographical information systems, drawing documentations etc. Well-known R-tree is one of the multidimensional data structures. The R-tree is based on bounding of spatial near points by multidimensional rectangles. This data structure supports various types of queries, e.g. point and range...

Only few multidimensional access methods have made their way into commercial relational DBMS. Even if a RDBMS ships with a multidimensional index, the multidimensional index usually is an add-on like Oracle SDO, which is not integrated into the SQL interpreter, query processor and query optimizer of the DBMS kernel. Our demonstration shows TransBase HyperCube, a commercial RDBMS, whose kernel f...