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Transcript of 1 Senn, Information Technology, 3 rd Edition © 2004 Pearson Prentice Hall James A. Senns...
1 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
James A. Senn’sInformation Technology, 3rd Edition
Chapter 7
Enterprise Databases and Data Warehouses
2 Senn, Information Technology, 3rd Edition© 2004 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 and their uses in business.
• Describe the differences between schemas, views, and indexes.
3 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Objectives (Continued)
• Discuss the benefits of client/server computing.
• Differentiate between shared and distributed databases.
• Explain why enterprises establish data warehouses and how they differ from data marts and enterprise databases.
4 Senn, Information Technology, 3rd Edition© 2004 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 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
The Principles of Data SharingDefinition
• 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 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
The Principles of Data SharingDefinition (Continued)
7 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
The Principles of Data SharingDatabase 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 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
The Principles of Data SharingDatabase Management Systems (Continued)
9 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresEnterprise 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.
10 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresEnterprise Data Model (Continued)
11 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresSchema
• Schema: The structure of a database.
• Schema for Relational Database– Relational Database: A database in which
the data are structured in a table format consisting of rows and columns.
12 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresSchema (Continued)
13 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresSchema (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.
14 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresSchema (Continued)
15 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresViews
• 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.
16 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresViews (Continued)
17 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresIndexes
• 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.
18 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Enterprise Database StructuresIndexes (Continued)
19 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Client/Server ComputingDefinition
• 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.
20 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Client/Server ComputingDefinition (Continued)
21 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Client/Server ComputingDefinition
22 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Client/Server ComputingDefinition (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.
23 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Client/Server ComputingThe Benefits of Client/Server Computing
24 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Databases on the InternetDefinition
• Web-based Integration: Makes data from enterprise databases available to users connecting through the Internet (including enterprise intranets and extranets).
25 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Databases on the InternetDefinition (Continued)
26 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Distributed DatabasesDefinition
• Shared Database: A database shared among many users and applications.
• 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.
27 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Distributed DatabasesPartitioning and Replication
• 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.
28 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Distributed DatabasesDistribution Strategies
• 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.
29 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Distributed DatabasesDesigned a Distributed Database
• Database Directory: The component of a shared database that keeps track of data and information.
• Other Design Factors– Storage Costs– Processing Costs– Communication Costs– Retrieval and Processing– Reliability– Frequency of Updates and Queries
30 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Distributed DatabasesDesigned a Distributed Database (Continued)
31 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Data Warehouses and OLAPDefinition
• Online Analytical Processing (OLAP): Database processing that selectively extracts data from different points of view.
• 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.
32 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
Data Warehouses and OLAPComparison of Enterprise Databases and Data Warehouses
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Data Warehouses and OLAPData Warehouse
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Data Warehouses and OLAPDefinition
• 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.
35 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
PeopleDefinition
• Database Administrator (DBA): The IT professional responsible for managing all the activities and procedures related to an organization’s database.
• Systems Programmer
36 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
ProceduresDatabase 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
37 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
ProceduresConcurrency 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.
38 Senn, Information Technology, 3rd Edition© 2004 Pearson Prentice Hall
ProceduresConcurrency 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.
• Deadlock: A situation in which each user of a database is waiting for the others to unlock a record.