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Lead Black Slide. Chapter 7. Information System Data Management. Our Agenda. File Processing Database Processing Database Organization Common Database Software Using Database Software Database Use in Information Systems. Our Agenda (cont’d.). Data Warehouses Multidimensional Databases
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Chapter 7 Information System Data Management © 2001 Business & Information Systems 2/e
Our Agenda • File Processing • Database Processing • Database Organization • Common Database Software • Using Database Software • Database Use in Information Systems © 2001 Business & Information Systems 2/e
Our Agenda (cont’d.) • Data Warehouses • Multidimensional Databases • Database Administration © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
File Processing Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Database Processing Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Database Organization Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Types of Databases • Hierarchical database • Network database • Relational database • Object-oriented database • Object-relational database © 2001 Business & Information Systems 2/e
Common Database Software Information System Data Management © 2001 Business & Information Systems 2/e
Personal Computer dBASE Access FoxPro Approach Fourth Dimension Oracle Networked Systems Oracle Sybase SQL Server Informix GemStone ObjectStore Versant ODBMS Common Database Software © 2001 Business & Information Systems 2/e
Using Database Software Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Database Use in Information Systems Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Data Warehouses Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Multidimensional Databases Information System Data Management © 2001 Business & Information Systems 2/e
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 © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Database Administration Information System Data Management © 2001 Business & Information Systems 2/e
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. © 2001 Business & Information Systems 2/e
Information Systems Data Management Key Terms © 2001 Business & Information Systems 2/e
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 Key Terms © 2001 Business & Information Systems 2/e
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 Key Terms (cont’d.) © 2001 Business & Information Systems 2/e
Relational Database Relationship Sequential File Shared Database SQL View Key Terms (cont’d.) © 2001 Business & Information Systems 2/e
Summary • File Processing • Database Processing • Database Organization • Common Database Software • Using Database Software • Database Use in Information Systems © 2001 Business & Information Systems 2/e
Summary (cont’d.) • Data Warehouses • Multidimensional Databases • Database Administration © 2001 Business & Information Systems 2/e