Database Systems Journal

ISSN 2069 - 3230

The journal is published under the sponsorship of
The Bucharest University of Economic Studies
and it is produced by the university's own publishing division,
The Bucharest University of Economic Studies Publishing House

Database Systems Journal, Vol. I, Issue 2/2010
Issue Topic: Database Systems

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1. Column-Oriented Databases, an Alternative for Analytical Environment (p. 3-16)
Gheorghe MATEI, Romanian Commercial Bank, Bucharest, Romania
It is widely accepted that a data warehouse is the central place of a Business Intelligence system. It stores all data that is relevant for the company, data that is acquired both from internal and external sources. Such a repository stores data from more years than a transactional system can do, and offer valuable information to its users to make the best decisions, based on accurate and reliable data. As the volume of data stored in an enterprise data warehouse becomes larger and larger, new approaches are needed to make the analytical system more efficient. This paper presents column-oriented databases, which are considered an element of the new generation of DBMS technology. The paper emphasizes the need and the advantages of these databases for an analytical environment and make a short presentation of two of the DBMS built in a columnar approach.
Keywords: Column-oriented database, row-oriented database, data warehouse, Business Intelligence, symmetric multiprocessing, massively parallel processing.
2. Optimized Data Indexing Algorithms for OLAP Systems (p. 17-26)
Lucian BORNAZ, University of Economic Studies, Bucharest, Romania
The need to process and analyze large data volumes, as well as to convey the information contained therein to decision makers naturally led to the development of OLAP systems. Similarly to SGBDs, OLAP systems must ensure optimum access to the storage environment. Although there are several ways to optimize database systems, implementing a correct data indexing solution is the most effective and less costly. Thus, OLAP uses indexing algorithms for relational data and n-dimensional summarized data stored in cubes. Today database systems implement derived indexing algorithms based on well-known Tree, Bitmap and Hash indexing algorithms. This is because no indexing algorithm provides the best performance for any particular situation (type, structure, data volume, application). This paper presents a new n-dimensional cube indexing algorithm, derived from the well known B-Tree index, which indexes data stored in data warehouses taking in consideration their multi-dimensional nature and provides better performance in comparison to the already implemented Tree-like index types.
Keywords: Data warehouse, indexing algorithm, OLAP, n-Tree.
3. Cost Effective RADIUS Authentication for Wireless Clients (p. 27-32)
Alexandru ENACEANU, Romanian-American University, Bucharest, Romania
Gabriel GARAIS, Romanian-American University, Bucharest, Romania
Network administrators need to keep administrative user information for each network device, but network devices usually support only limited functions for user management. WLAN security is a modern problem that needs to be solved and it requires a lot of overhead especially when applied to corporate wireless networks. Administrators can set up a RADIUS server that uses an external database server to handle authentication, authorization, and accounting for network security issues.
Keywords: RADIUS, WLAN, Wireless Authentication, Wireless Access Control.
4. Database Replication (p. 33-38)
Marius Cristian MAZILU, University of Economic Studies, Bucharest, Romania
For someone who has worked in an environment in which the same database is used for data entry and reporting, or perhaps managed a single database server that was utilized by too many users, the advantages brought by data replication are clear. The main purpose of this paper is to emphasize those advantages as well as presenting the different types of Database Replication and the cases in which their use is recommended.
Keywords: Database Replication, Snapshot replication, Merge replication, Transactional replication.
5. Integration of Web Technologies in Software Applications. Is Web 2.0 a Solution? (p. 39-44)
Cezar Liviu CERVINSCHI, University of Economic Studies, Bucharest, Romania
Diana BUTUCEA, University of Economic Studies, Bucharest, Romania
Starting from the idea that Web 2.0 represents “the era of dynamic web”, the paper proposes to provide arguments (demonstrated by physical results) regarding the question that is at the foundation if this article. Due to the findings we can definitely affirm that Web 2.0 is a solution to building powerful and robust software, since the Internet has become more than just a simple presence on the users’ desktop that develops easy access to information, services, entertainment, online transactions, e-commerce, e-learning and so on, but basically every kind of human or institutional interaction can happen online. This paper seeks to study the impact of two of these braches upon the user – e-commerce and e-testing. The statistic reports will be made on different sets of people, while the conclusions are the results of a detailed research and study of the applications’ behaviour in the actual operating environment.
Keywords: Web 2.0, web technology, e-commerce, online transaction, e-testing.
6. Commercially Available Data Mining Tools used in the Economic Environment (p. 45-54)
Mihai ANDRONIE, University of Economic Studies, Bucharest, Romania
Daniel CRISAN, Eidgenössische Technische Hochschule Zürich, Switzerland
This paper presents some of the most common commercially available data mining tools, with their most important features, side by side, and some considerations regarding the evaluation of data mining tools by companies that want to acquire such a system. Among some of the most important factors that a company has to take into account are the amounts of data available, how it is stored and the data mining tasks that must be performed, but there are also others. Not the last it should be mentioned that the cost of a data mining system is important for a company, having a limiting effect on the expansion of the data mining products market towards small companies.
Keywords: Data Mining, Data Analysis, Information System, Data Mining Tools.
7. Database Optimizing Services (p. 55-60)
Adrian GHENCEA, University Titu Maiorescu Bucharest, Romania
Immo GIEGER, Bodenstedt-Wilhelmschule, Peine, Germany
Almost every organization has at its centre a database. The database provides support for conducting different activities, whether it is production, sales and marketing or internal operations. Every day, a database is accessed for help in strategic decisions. The satisfaction therefore of such needs is entailed with a high quality security and availability. Those needs can be realised using a DBMS (Database Management System) which is, in fact, software for a database. Technically speaking, it is software which uses a standard method of cataloguing, recovery, and running different data queries. DBMS manages the input data, organizes it, and provides ways of modifying or extracting the data by its users or other programs. Managing the database is an operation that requires periodical updates, optimizing and monitoring.
Keywords: Database, database management system (DBMS), indexing, optimizing, cost for optimized databases.