1. 1 Adapted from Pearson Prentice Hall Adapted form James A. Senn’s Information Technology, 3 rd Edition Chapter 7 Enterprise Databases and Data Warehouses

2. 2 Adapted from Pearson Prentice Hall Objectives Identify the reasons organizations choose to share databases and the functions of a database management system. Explain the difference between relational and object-oriented databases. Describe the differences between schemas, views, and indexes.

3. 3 Adapted from Pearson Prentice Hall Objectives (Continued) Discuss the benefits of client/server computing. Explain shared and distributed databases. Explain why enterprises establish data warehouses and how they differ from data marts and enterprise databases.

4. 4 Adapted from Pearson Prentice Hall Objectives (Continued) Distinguish between a database administrator and a system programmer. Discuss database administration procedures and concurrency procedures and explain why these are an essential part of a shared database system.

5. 5 Adapted from Pearson Prentice Hall The Principles of Data Sharing Definition Database: A collection of data and information describing items of interest to an organization. Entity: A person, place, thing, event or condition about which data and information are collected. Enterprise Database: A collection of data designed to be shared by many users within an organization.

6. 6 Adapted from Pearson Prentice Hall The Principles of Data Sharing Definition (Continued)

7. 7 Adapted from Pearson Prentice Hall The Principles of Data Sharing Database Management Systems Database Management Systems (DBMS): A program that makes it possible for users to manage the data in a database in order to increase accessibility and productivity. The Functions of Database Management: –Integrating Databases –Reducing Redundancy –Sharing Information –Maintaining Integrity –Enabling Database Evolution

8. 8 Adapted from Pearson Prentice Hall Enterprise Database Structures Enterprise Data Model Enterprise Data Model/Entity Relationship: A graphical representation of the items (the entities) of interest about which data is captured and stored in the database. COAL EXAMPLE

9. 9 Adapted from Pearson Prentice Hall Enterprise Database Structures Enterprise Data Model (Continued)

10. 10 Adapted from Pearson Prentice Hall Enterprise Database Structures Schema Schema: The structure of a database. Schema for Relational Database –Relational Database: A database in which the data are structured in a table format (relation) consisting of rows (records or tuples) and columns (attributes, or fields).

11. 11 Adapted from Pearson Prentice Hall Enterprise Database Structures Schema (Continued)

12. 12 Adapted from Pearson Prentice Hall Enterprise Database Structures Schema (Continued) Schema for Object-Oriented Database –Object-oriented Database: A database that stores data and information about objects. –Object: A component that contains data about itself and how it is to be processed. –Action/Method: An instruction that tells a database how to process an object to produce specific information.

13. 13 Adapted from Pearson Prentice Hall Enterprise Database Structures Schema (Continued)

14. 14 Adapted from Pearson Prentice Hall Enterprise Database Structures Views View: A subset of one or more databases, created either by extracting copies of records from a database or by merging copies of records from multiple databases.

15. 15 Adapted from Pearson Prentice Hall Enterprise Database Structures Views (Continued)

16. 16 Adapted from Pearson Prentice Hall Enterprise Database Structures Indexes Index: A data file that contains identifying information about each record and its location in storage. Record Key: In a database, a designated field used to distinguish one record from another. e.g. your student number vs. your name. Which one to use?

17. 17 Adapted from Pearson Prentice Hall Enterprise Database Structures Indexes (Continued)

18. 18 Adapted from Pearson Prentice Hall Client/Server Computing Definition File Server: A computer containing files that are available to all users interconnected on a local area network. Client/Server Computing: A type of computing in which all data and information retrieval requests and responses pass over a network. Much of the processing is performed on the server and the results of the processing are transmitted to the client.

19. 19 Adapted from Pearson Prentice Hall Client/Server Computing Definition (Continued)

20. 20 Adapted from Pearson Prentice Hall Client/Server Computing Definition

21. 21 Adapted from Pearson Prentice Hall Client/Server Computing Definition (Continued) Client: In client-server computing, a desktop workstation. Server: A computer that hosts a network and provides the resources that are shared on the network.

22. 22 Adapted from Pearson Prentice Hall Client/Server Computing The Benefits of Client/Server Computing

23. 23 Adapted from Pearson Prentice Hall Databases on the Internet Definition Web-based Integration: Makes data from enterprise databases available to users connecting through the Internet (including enterprise intranets and extranets).

24. 24 Adapted from Pearson Prentice Hall Databases on the Internet Definition (Continued) Airline companies, car rental companies, banks are among the examples

25. 25 Adapted from Pearson Prentice Hall Distributed Databases Definition Shared Database: A database shared among many users and applications. A shared database can also be a distributed database. Distributed Database: A database that resides in more than one system in a distributed network. Each component of the database can be retrieved from any node in the network.

26. 26 Adapted from Pearson Prentice Hall Distributed Databases Partitioning and Replication Databases can be distributed in two ways: Partitioning: A method of database distribution in which different portions of the database reside at different nodes in the network. Replication: A method of database distribution in which one database contains data that are included in another database. …but databases should avoid redundancies, how replication is desired then?  To avoid network traffic

27. 27 Adapted from Pearson Prentice Hall Distributed Databases Distribution Strategies Distribution strategies can be decided according to business. HOW? Geographic Distribution Strategy: A database distribution strategy in which the database is located in a region where the data and information are used most frequently. Functional Distribution Strategy: A database distribution strategy in which the database is distributed according to business functions.

28. 28 Adapted from Pearson Prentice Hall Distributed Databases Designed a Distributed Database Design Factors –Ease of use The user does not have to know how the technical details are handled. For example: Database Directory: The component of a shared database that keeps track of the location of data and information. e.g. Telephone network –Storage Costs –Processing Costs –Communication Costs –Retrieval and Processing –Reliability –Frequency of Updates and Queries

29. 29 Adapted from Pearson Prentice Hall Distributed Databases Designed a Distributed Database (Continued)

30. 30 Adapted from Pearson Prentice Hall Data Warehouses and OLAP Definition Online Analytical Processing (OLAP): Database processing that selectively extracts data from different points of view. Data warehouse and data mining are useful as data sources in OLAP to discover new patterns. Data Warehouse: A large data store, designed from inquiries, that combines details of both current and historical operations, usually drawn from a number of sources.

31. 31 Adapted from Pearson Prentice Hall Data Warehouses and OLAP Comparison of Enterprise Databases and Data Warehouses Data warehouses are not replacements for enterprise databases They can retrieve data from multiple databases. They can combine both historical and recent data to help managers in multiple enterprise activities that are beyond individual database capacities.

32. 32 Adapted from Pearson Prentice Hall Data Warehouses and OLAP Data Warehouse

33. 33 Adapted from Pearson Prentice Hall Data Warehouses and OLAP Definition Data Mining: Uses software designed to detect information hidden in the data. Data Marts: Processed to focus on a specific area of activities or isolated scientific or commercial processes. Basically, a data mart is a smaller and narrowly focused versions of a data warehouse.

34. 34 Adapted from Pearson Prentice Hall People Definition Data marts, data warehouses and enterprise databases require specialists: Database Administrator (DBA)/Data Administrator: The IT professional responsible for managing all the activities and procedures related to an organization’s database. Sometimes it is a teamwork. Their primary job is to manage the database. Systems Programmer: A software and hardware specialist working with physical details of the database of the computer’s operating system. They do not always work on database activities.

35. 35 Adapted from Pearson Prentice Hall Procedures Database Administration Procedures Database Administration Procedures: The procedures associated with managing a database. –Database Planning –Database Design –Database Creation –Database Maintenance –Analysis of Usage –Creation and Monitoring of Security Procedures

36. 36 Adapted from Pearson Prentice Hall Procedures Concurrency Procedures Concurrent Data Sharing: A database procedure that allows several users to access the database simultaneously. Nonconcurrent Data Sharing: A database procedure that allows individuals to access a database only when no other person or application is processing the data.

37. 37 Adapted from Pearson Prentice Hall Procedures Concurrency Procedures (Continued) Record Locking: A concurrency procedure that prohibits another user from accessing or altering a records that is in use. File Locking: Used in systems that store unstructured information and have file-level sharing. e.g. A Word document may be locked until the user closes it. Deadlock: A situation in which each user of a database is waiting for the others to unlock a record.