Database System

Abstract. Data represent today a valuable asset for organizations and compa-nies and must be protected. Ensuring the security and privacy of data assets is a crucial and very difficult problem in our modern networked world. Despite the necessity of protecting information stored in ...

The most valuable information assets of an organization are often stored in databases and it is pertinent for such organizations to ensure the integrity and confidentiality of their databases. With the proliferation of ecommerce sites that are backed by database systems, databases that are available online 24 7 are ubiquitous. Data in these databases ranges from credit card numbers to personal medical records. Failing to protect these databases from intrusions will result in loss of customers’ confidence and might even result in lawsuits. Database intrusion refers to the unauthorized access and misuse of database systems. Database intrusion detection systems identify suspicious, abnormal or downright malicious accesses to the database system. However, there is little existing work on detecting intrusions in databases. We present a technique that can efficiently identify anomalous accesses to the database. Our technique charaterizes legitimate accesses through fingerprinting their co...

Research using the model system Xenopus laevis has provided critical insights into the mechanisms of early vertebrate development and cell biology. Large scale sequencing efforts have provided an increasingly important resource for researchers. To provide full advantage of the available sequence, we have analyzed 350,468 Xenopus laevis Expressed Sequence Tags (ESTs) both to identify full length protein encoding sequences and to develop a unique database system to support comparative approaches between X. laevis and other model systems. Using a suffix array based clustering approach, we have identified 25,971 clusters and 40,877 singleton sequences. Generation of a consensus sequence for each cluster resulted in 31,353 tentative contig and 4,801 singleton sequences. Using both BLASTX and FASTY comparison to five model organisms and the NR protein database, more than 15,000 sequences are predicted to encode full length proteins and these have been matched to publicly available IMAGE c...

This paper describes how the CAGIS environment can be used to manage work-processes, cooperative processes, and how to share and control information in a distributed, heterogeneous environment. We have used a conference organising process as a scenario and applied our CAGIS environment on this process. The CAGIS environment consists of three main parts: a document management system, a process management system, and a transaction management system. Keywords: Web-based software engineering, Internet computing: JAVA, XML, Intelligent agent software, Database systems, Document modelling, Process modelling, Transaction modelling. 1 Introduction After the introduction of the Internet, more and more projects are taking place in heterogeneous environments where both people, information and working processes are distributed. Work is often dynamic and cooperative and involves multiple actors with different kinds of needs. In these settings there is a need to help people coordinate their ...

This introduction to database systems offers a comprehensive approach, focusing on database design, database use, and implementation of database applications and database management systems. KEY TOPICS: The first half of the book provides in-depth coverage of databases ...

This paper surveys many variants of concurrency control algorithms in database systems. We classify the different alternatives under locking, time-stamp, optimistic algorithms. Though the performance of different concurrency control algorithms have been explored extensively for database management systems but to the best of author's knowledge, the relative variants of different protocols used for concurrency control algorithms have not been reported yet.

Database systems are a key component behind many of today’s computer systems. As a consequence, it is crucial that database systems provide correct and contin- uous service despite unpredictable circumstances, such as software bugs or attacks. This paper presents the de- sign of Byzantium, a Byzantine fault-tolerant database replication middleware that provides snapshot isolation (SI) semantics. SI is very popular because it allows in- creased concurrency when compared to serializability, while providing similar behavior for typical workloads. Thus, Byzantium improves on existing proposals by al- lowing increased concurrency and not relying on any centralized component. Our middleware can be used with off-the-shelf database systems and it is built on top of an existing BFT library.

Machine learning is an emerging field of computer science concerned with the learning of knowledge from exploration of already stored data. However, effective utilization of extracted knowledge is an important issue. Extracted knowledge may be best utilized via feeding to knowledge based system. To this end, the work reported in this paper is based on a novel idea to enhance the productivity of the previously developed systems. This paper presents the proposed architecture of a Learning Apprentice System in Medical Billing system being developed for medical claim processing. A new dimension is added whereby, the process of extracting and utilization of knowledge are implemented in relational database environment for improved performance. It opens enormous application areas as most business data is in relational format managed by some relational database management server. The major components of the proposed system include knowledge base, rule engine, knowledge editor, and data mini...

This introduction to database systems offers a comprehensive approach, focusing on database design, database use, and implementation of database applications and database management systems. KEY TOPICS: The first half of the book provides in-depth coverage of databases ...