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2 Chapter 7 Information System Data Management

Powered by DeSiaMore3 Our Agenda File Processing Database Processing Database Organization Common Database Software Using Database Software Database Use in Information Systems

Powered by DeSiaMore4 Our Agenda (cont’d.) Data Warehouses Multidimensional Databases Database Administration

Powered by DeSiaMore5 Learning Objectives List advantages and disadvantages of file processing. Explain what a database is and what a database management system does. List advantages and disadvantages of database processing. Identify the main types of relationships in database processing.

Powered by DeSiaMore6 Learning Objectives (cont’d.) Explain the organization of relational databases. Describe the differences between database software for personal computers, multiple-user computers and networked computers. Describe several ways of using database software.

Powered by DeSiaMore7 Learning Objectives (cont’d.) Describe the use of databases in different types of information systems. Explain what a data warehouse is and what is meant by data mining. Describe multidimensional databases and explain on-line analytical processing.

Powered by DeSiaMore8 File Processing Information System Data Management

Powered by DeSiaMore9 File Processing Files consist of related records. Records consist of related fields. Fields consist of related characters. Files must contain a key field – a field where each record’s occurrence is unique.

Powered by DeSiaMore10 File Organization A file can be organized in secondary storage as a: Sequential file – records are organized one after the other and each record must be scanned to until the desired record is located. Direct or Random file – records are not necessarily stored in sequence and can be accessed directly.

Powered by DeSiaMore11 File Organization (cont’d.) A file can be organized in secondary storage as a: Indexed file – records are stored in one file and the organization of those records is stored in a second file. To use an indexed file both files, the data file and the index file, must be used together.

Powered by DeSiaMore12 File Management Managing data files requires that the data be kept up to date. To do so requires: Modifying, or updating, records involves Adding records Deleting records Changing records Data Validation – ensuring the data is accurate and secure.

Powered by DeSiaMore13 Advantages and Disadvantages of File Processing Advantages Simple to use. Disadvantages Processing data in more than one related file. Difficult to access data from more than one file at a time. Dependency between programs and data.

Powered by DeSiaMore14 Database Processing Information System Data Management

Powered by DeSiaMore15 Database Processing To overcome some of the disadvantages of file processing, database processing is used instead. The database software is called a DataBase Management System (DBMS). A database is a collection of data and relationships between data stored in secondary storage.

Powered by DeSiaMore16 Advantages and Disadvantages of Database Processing Advantages Duplication of data is reduced. Easier to process different groups of data. Not dependent on the organization of data in the database. Disadvantages Expensive. More vulnerable than file processing. Can be complex to develop.

Powered by DeSiaMore17 Database Organization Information System Data Management

Powered by DeSiaMore18 Data Relationships One-to-one relationship One group of data is related on only one other group of data. One-to-many relationship One group of data is related to one or more other groups of data. Many-to-many relationship One or more groups of data is related to one or more other groups of data.

Powered by DeSiaMore19 Types of Databases Hierarchical database Network database Relational database Object-oriented database Object-relational database

Powered by DeSiaMore20 Common Database Software Information System Data Management

Powered by DeSiaMore21 Common Database Software Personal Computer dBASE Access FoxPro Approach Fourth Dimension Oracle Networked Systems Oracle Sybase SQL Server Informix GemStone ObjectStore Versant ODBMS

Powered by DeSiaMore22 Using Database Software Information System Data Management

Powered by DeSiaMore23 Using Database Software Query languages – allows a user to query a database. SQL is a widely used query language. Query-By-Example (QBE) – is a graphical approach to query languages. A host language is a programming language for writing application programs containing commands from a query language.

Powered by DeSiaMore24 Database Use in Information Systems Information System Data Management

Powered by DeSiaMore25 Types of Databases Personal databases are generally used by only one person. Shared databases are used by many users at one time. To prevent users from processing data they do not need, the database is divided into views.

Powered by DeSiaMore26 Data Warehouses Information System Data Management

Powered by DeSiaMore27 Data Warehouses A data warehouse is a collection of data drawn from other databases used by the business. A data mart represents the specific data from a data warehouse which a user needs. Data mining is the technique of searching for patterns in the data.

Powered by DeSiaMore28 Multidimensional Databases Information System Data Management

Powered by DeSiaMore29 Multidimensional Databases A multidimensional database presents the data to the user in several dimensions. A three dimensional database might present the information by Sales Region Season Product Line

Powered by DeSiaMore30 On-Line Analytical Processing On-Line Analytical Processing (OLAP) permits users to “slice and dice” large amounts of data in databases, data warehouses, and multidimensional databases using a variety of techniques, including statistical techniques.

Powered by DeSiaMore31 Database Administration Information System Data Management

Powered by DeSiaMore32 Database Administration An organization with large databases often has a Database Administrator (DBA) who is responsible for managing the organization’s database. The DBA designs the databases based on the needs of the users.

Powered by DeSiaMore33 Information Systems Data Management Key Terms

Powered by DeSiaMore34 Key Terms Application Generator Database Database Administrator (DBA) Database Management System (DBMS) Data Mart Data Mining Data Warehouse Data Validation Direct (Random) File Distributed Database Hierarchical Database Host Language Indexed File Key Field Many-to-Many Relationship

Powered by DeSiaMore35 Key Terms (cont’d.) Multidimensional Database Network Database Object-Oriented Database Object-Relational Database One-to-Many Relationship One-to-One Relationship On-line Analytical Processing (OLAP) Personal Database Primary Key Query-by-Example (QBE) Query Language

Powered by DeSiaMore36 Key Terms (cont’d.) Relational Database Relationship Sequential File Shared Database SQL View

Powered by DeSiaMore37 Summary File Processing Database Processing Database Organization Common Database Software Using Database Software Database Use in Information Systems

Powered by DeSiaMore38 Summary (cont’d.) Data Warehouses Multidimensional Databases Database Administration

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