Chapter 5 Lecture 2

Principles of Information Systems2 Objectives Understand Data definition language (DDL) and data dictionary Learn about popular DBMSs Understand types of Data Warehouses Conceptually understand ODBC

Principles of Information Systems3 Creating and Modifying the Database Data definition language (DDL) A collection of instructions and commands used to define and describe data and data relationships in a specific database Allows the database’s creator to describe the data and the data relationships that are to be contained in the schema and subschemas Data dictionary: a detailed description of all the data used in the database

Principles of Information Systems4 Figure 5.11: Using a Data Definition Language to Define a Schema

Principles of Information Systems5 Figure 5.12: A Typical Data Dictionary Entry

Principles of Information Systems6 Storing and Retrieving Data When an application program request data from DBMS, the application program follows a logical access path When the DBMS goes to a storage device to retrieve the requested data, it follows a path to the physical location (physical access path) where the data is stored

Principles of Information Systems7 Figure 5.13: Logical and Physical Access Paths

Principles of Information Systems8 Manipulating Data and Generating Reports Data manipulation language (DML): the commands that are used to manipulate the data in a database Structured Query Language (SQL): adopted by the American National Standards Institute (ANSI) as the standard query language for relational databases Once a database has been set up and loaded with data, it can produce reports, documents, and other outputs

Principles of Information Systems9 Table 5.6: Examples of SQL Commands

Principles of Information Systems10 Popular Database Management Systems Popular DBMSs for end users include Microsoft’s Access and Corel’s Paradox The complete database management software market includes databases by IBM, Oracle, and Microsoft Examples of open-source database systems: PostgreSQL and MySQL Many traditional database programs are now available on open-source operating systems

Principles of Information Systems11 Selecting a Database Management System Important characteristics of databases to consider: Size of the database Number of concurrent users Performance The ability of the DBMS to be integrated with other systems

Principles of Information Systems12 Selecting a Database Management System (continued) Important characteristics of databases to consider (continued): Features of the DBMS Vendor considerations Cost of the system

Principles of Information Systems13 Database Applications: Linking the Company Database to the Internet Corporate databases can be accessed by customers, suppliers, and company employees through: The Internet Intranets Extranets Semantic Web: a seamless integration of traditional databases with the Internet

Principles of Information Systems14 Data Warehouses, Data Marts, and Data Mining Data warehouse: a database that collects business information from many sources in the enterprise, covering all aspects of the company’s processes, products, and customers Data mart: a subset of a data warehouse Data mining: an information-analysis tool that involves the automated discovery of patterns and relationships in a data warehouse

Principles of Information Systems15 Figure 5.17: Elements of a Data Warehouse

Principles of Information Systems16 Table 5.8: Common Data-Mining Applications

Principles of Information Systems17 Business Intelligence Business intelligence (BI): the process of gathering enough of the right information in a timely manner and usable form and analyzing it to have a positive impact on business strategy, tactics, or operations Knowledge management: the process of capturing a company’s collective expertise wherever it resides and distributing it wherever it can help produce the biggest payoff

Principles of Information Systems18 Distributed Databases Distributed database A database in which the data may be spread across several smaller databases connected via telecommunications devices Corporations get more flexibility in how databases are organized and used Replicated database: a database that holds a duplicate set of frequently used data

Principles of Information Systems19 Online Analytical Processing (OLAP) Software that allows users to explore data from a number of different perspectives Table 5.9: Comparison of OLAP and Data Mining

Principles of Information Systems20 Open Database Connectivity (ODBC) Standards that ensure that software can be used with any ODBC-compliant database Can be used to export, import, or link tables between different applications

Principles of Information Systems21 Figure 5.19: Advantages of ODBC

Principles of Information Systems22 Object-Oriented and Object-Relational Database Management Systems Object-oriented database Stores both data and its processing instructions Method: a procedure or action Message: a request to execute or run a method

Principles of Information Systems23 Object-Oriented and Object-Relational Database Management Systems (continued) Object-oriented database management system (OODBMS): group of programs that manipulate an object-oriented database and provide a user interface and connections to other application programs Object-relational database management system (ORDBMS): DBMS capable of manipulating audio, video, and graphical data

Principles of Information Systems24 Summary Hierarchy of data: bits, characters, fields, records, files, and databases Entity: a generalized class of things (objects) for which data is collected, stored, and maintained Attribute: characteristic of an entity Data model: diagram of entities and relationships Relational model: describes data in which all elements are placed in two-dimensional tables called relations

Principles of Information Systems25 Summary (continued) Selecting: eliminates rows according to certain criteria Projecting: eliminates columns in a table Database management system (DBMS): group of programs used as an interface Between a database and application programs Database and the user Data dictionary: detailed description of all the data used in the database

Principles of Information Systems26 Summary (continued) Data warehouse: database that collects business information from all aspects of a company’s processes, products, and customers Data mining: an information-analysis tool for the automated discovery of patterns and relationships in a data warehouse Open database connectivity (ODBC) standards: ensure that software can be used with any ODBC-compliant database