Designed as a textbook for students offering courses in computer science engineering, master of computer applications (MCA) and for IT courses, this comprehensive and up-to-date study gives a clear analysis of the applications of both Oracle and Sybase-the enterprise class of relational databases. Realizing the importance of modern topics for the IT-savvy readers, the author has devoted separate chapters to the latest features of the database such as dynamic hashing, replication, distributed databases, query optimization, auditing and high availability subsystem. These are strategically and tactically very important from the viewpoint of database performance, recovery, availability and database adminis-tration. Besides, legacy databases, for example, hierarchical IMS of IBM and network data model DBTG, are given due importance. Oracle and Sybase systems, their architecture, SQL, PL/SQL and T-SQL, have also been discussed with focus on their thematic interrelationships. A highlight of the text is the inclusion of a chapter on the concepts of symmetrical and asymmetrical configurations related to high-availability subsystem and basic copy model of Replication Technology along with two-phase commit protocol used in distributed databases. This takes the students beyond the average discussion of this technology.Table of ContentsPreface.1. Introduction.2. The Entity-Relationship Model.3. Data Models.4. Storage Structure.5. Relational Data Structure.6. Architecture of System R and Oracle.7. Normalization.8. Structured Query Language.9. T-SQL-Triggers and Dynamic Execution.10.Procedure Language-SQL.11.Cursor Management and Advanced PL/SQL.12.Relational Algebra and Relational Calculus.13.Concurrency Control and Automatic Recovery.14.Distributed Database and Replication.15.Higher Availability and RAID Technology.16.Security Features Built in RDBMS.17.Queries Optimization.18.Architecture of a Hierarchical DBMS.19.The Architecture of Network-Based DBTG System.20.Comparison between Different Data Models.References.Answers to Selected Exercises.Index..