The University of Akron Dept of Business Technology Computer Information Systems

1. The University of AkronDept of Business TechnologyComputer Information Systems Database Management Approaches 2440: 180Database Concepts Instructor: Enoch E. Damson

2. Distributed Databases • Computers at various sites • Connected with communications network • Distributed database is single logical database physically divided among networked computers • DDBMS supports and manipulates distributed databases Database Management Approaches

3. Characteristics ofDistributed DBMSs • Homogeneous • Same local DBMS at each site • Heterogeneous • At least two sites with different DBMSs Database Management Approaches

4. Characteristics ofDistributed DBMSs… • Location transparency • User feels as though entire database is at their site • Replication transparency • User unaware of behind the scenes replication of the data • Fragmentation transparency • Logical object divided among various locations Database Management Approaches

5. Advantages of Distributed Databases • Local control of data • Possible legal reasons for local control over data used in a particular geographic region • Increased database capability • Added system availability • Though parts of a database may not be accessible, transactions can still occur, increasing overall availability of the database • Added efficiency • Smaller tables are faster to query Database Management Approaches

6. Disadvantages of Distributed Databases • Problems updating replicated data • More complex query processing • More complex treatment of concurrent update • More complex recovery measures • More difficult management of the data dictionary • More complex database design Database Management Approaches

7. Rules for Distributed Databases • Local autonomy • No reliance on a central site • Continuous operation • Location transparency • Fragmentation transparency • Replication transparency Database Management Approaches

8. Rules for Distributed Databases… • Distributed query processing • Distributed transaction management • Hardware independence • Operating system independence • Network independence • DBMS independence Database Management Approaches

9. Client-Server Systems • Tiered approach to developing systems • Typical systems will implement two tiers • Client • Server • Server manages all access to data • Client consults server for most processing • Some systems almost totally abstract the client from any processing by introducing a middle tier to handle all logic or processing Database Management Approaches

10. Advantages ofClient/Server Systems • Lower network traffic • Improved processing distribution • Thinner clients • Greater processing transparency Database Management Approaches

11. Advantages ofClient/Server Systems… • Increased network, hardware, and software transparency • Improved security • Decreased costs • Increased scalability Database Management Approaches

12. Triggers and Stored Procedures • Triggers • Actions that occurs automatically in response to a particular database operation • Created by programmers • Use special SQL statements • Stored Procedures • Collection of SQL statements compiled and optimized by DBMS • Improves performance Database Management Approaches

13. Data Warehouses • Subject-oriented, integrated, time-variant, nonvolatile collection of data in support of management’s decision-making process • Used for analysis of existing data • Resolves performance issues suffered by operational RDBMSs and OLTPs Database Management Approaches

14. On-Line Analytical Processing • Optimized to work with data warehouses • Used to answer questions • Allows users to perceive data as a multidimensional data cube • Slice and dice • Drill down • Roll Up • Data mining Database Management Approaches

15. Rules for OLAP Systems • Multidimensional conceptual view • Transparency • Accessibility • Consistent reporting performance • Client/server architecture • Generic dimensionality Database Management Approaches

16. Rules for OLAP Systems • Dynamic sparse matrix handling • Multiuser support • Unrestricted, cross-dimensional operations • Intuitive data manipulation • Flexible reporting • Unlimited dimensions and aggregation levels Database Management Approaches

17. Object-Oriented DBMS (OODBMS) • System in which data and methods operating on that data are encapsulated into objects • Store graphics, drawings, video, sound, and other complex objects called binary large objects (BLOBs) • General concepts • Objects and classes • Methods and messages • Inheritance Database Management Approaches

18. Unified Modeling Language (UML) • Models various aspects of software development for OO systems • Includes several types of diagrams • Class • Use Case • State • Sequence • Activity • Collaboration • Component Database Management Approaches

19. Class Diagram with Constraints Database Management Approaches

20. Class Diagram with a Generalization and a Constraint Database Management Approaches

21. Rules for OODBMSs • Complex objects • Object identity • Encapsulation • Information hiding • Types of classes • Inheritance • Late binding Database Management Approaches

22. Rules for OODBMSs… • Computational completeness • Extensibility • Persistence • Performance • Concurrent update support • Recovery support • Query facility Database Management Approaches

23. Web Access to Databases • Electronic Commerce • Conducting business on the Internet • Business to Business • Business to Consumer • Internet facilitating better access to data • Extensible Markup Language (XML) • Key technology to data interchange between systems Database Management Approaches

24. History of Database Management • Early systems • GUAM, DL/I, IMS, IDS, IDMS • Relational products • DB2, Oracle, Sybase, Paradox, dBASE, Access, MySQL, SQL Server • OODBMSs • Gemstone, Objectivity/DB, Versant • ORDBMSs Database Management Approaches

25. Hierarchical and Network Databases • Data models have two components, structure and operations • Structure is how users perceive data to be structured • Operations are facilities given to users to interact with data • Users perceive a network model database as a collection of record types and relationships • Users perceive a hierarchical model as a collection of hierarchies or trees Database Management Approaches