Stream databases Strumieniowe Bazy Danych Przemysław Pawluk Supervisors: prof. Zygmunt Mazur (Wroclaw University of Technology) prof. Lars Lundberg (Blekinge Institute of Technology) Institute of Applied Informatics Department of Computer Science and Management Wroclaw University of Technology

2/12 Agenda Introduction Data model Continuous Query Languages Results of the work Possible usage Summary

3/12 Introduction Goals of the thesis: Stream model presentation Presentation of complexity assessment method Consideration of pros and cons of the stream model

4/12 Data model Stream data model is an extension of relational data model. Data elements arrived on-line and stay only for a limited time period Data from the stream could be stored as relation The relation could be transformed into the stream

5/12 Continuous Query Languages Declarative extension of SQL Project STREAM Project TelegraphCQ Procedural Project Aurora Languages taxonomy Lack of standard!

6/12 Results of the work (1) To consider pros and cons of stream databases two models have been compared Complexity of models has been assessed As a basis of design process the Hofmeister’s method has been used

7/12 Results of the work (2) Models have been transformed into Weighted Class Dependence Graph To enable processing graphs have been presented in the form of matrix The measure of complexity of the model is entropy

8/12 Results of the work (3) Model based on stream database has lower complexity (7,3%) Lower complexity can influence costs of development and maintenance of the system Usage of stream databases in telecommunication system could be profitable

9/12 Results of the work (4) Issues in the thesis: Strong dependency on experience Special character of data Only academic implementation are available (problem with comparison of i.e. performance)

10/12 Possible usage Telecommunication Medicine Army … Where data can be perceived as a stream

11/12 Summary New class of database systems has been presented Method of complexity assessment has been described Two models have been compared in the context of complexity Possibility usage stream databases in telecommunication systems has been considered

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