1. l The Difference Between Logical and Physical Views of Information l Databases and Database Management Systems l How You Can Develop Database Applications l Data Warehouses and Data Mining Tools Introduction DATABASES AND DATA WAREHOUSES A Gold Mine of Information

2. Today, Organizations Need... l Information to compete effectively l Information just to stay alive in the information age l Information organized in such a way that you can easily and quickly get to it l Information-processing tools that help you work with information Introduction

3. THREE THINGS ORGANIZATIONS DO WITH INFORMATION 1.Process information in the form of transactions 2.Use information to make a decision 3.Manage information while it’s used Information Revisited

4. PROCESSING INFORMATION IN THE FORM OF TRANSACTIONS l Such as payroll processing, order processing, and handling your registration requests for classes. l This is called ONLINE TRANSACTION PROCESSING (OLTP) - the gathering of input information, processing that information, and updating existing information to reflect the gathered and processed information. l Operational databases support OLTP. Information Revisited

5. USING INFORMATION TO MAKE A DECISION l For answering such questions as, “How many senior-level marketing majors have not taken statistics?” l This is called ONLINE ANALYTICAL PROCESSING (OLAP) - the manipulation of information to support decision making. l Data warehouses support OLAP. Information Revisited

6. MANAGING INFORMATION WHILE IT’S USED l Determining who can view or use information l Specifying how to back up information l Identifying what storage technologies to use Information Revisited Most importantly, managing information includes organizing it so that people can logically use it without having to know anything about its physical structure. The difference between logical and physical is key.

7. l In managing information, physical deals with the structure of information as it resides on various storage media. l Logical deals with how knowledge workers view their information needs, and includes such terms as: –CHARACTER - our smallest unit of information. –FIELD - group of related characters. –RECORD - group of related fields. –FILE - group of related records. –DATABASE - group of logically associated files. –DATA WAREHOUSE - information from many databases. Information Revisited

8. DATABASE A database is actually composed of two parts: 1. the information itself –the files that are logically associated 2. the logical structure of the information –called the data dictionary Databases a collection of information that you organize and access according to the logical structure of that information.

9. A Database Is a Collection of Information l Most databases contain two or more files with related information. l The Inventory database (Figure 4.4, page 125) contains two files - Part and Facility. l These two files are logically related because parts are stored in facilities and because you would use both of these files to manage your inventory. Databases

10. A Database Contains a Logical Structure l You organize and access a database by its logical structure, not its physical position. l DATA DICTIONARY - contains the logical structure of information in a database. l The data dictionary contains the logical properties that describe information in a database. l See Figure 4.5 (page 134) for the data dictionary of the Percentage Markup field in the Inventory database. Databases

11. A Database Has Logical Ties Among the Information l A PRIMARY KEY is a field in a database file that uniquely describes each record. l A FOREIGN KEY is a primary key of one file that also appears in another file. So, foreign keys specify how files are logically related. l For example, the Part and Facility files are logically related. So, in Figure 4.4 you can see that Facility Number (the primary key for the Facility file) exists in the Part file (where it’s a foreign key). Databases

12. A Database Contains Built-in Integrity Constraints l An INTEGRITY CONSTRAINT is a rule that helps assure the quality of the information in a database. l A registration database at your school includes integrity constraints concerning prerequisites for certain classes. l Our Inventory database includes an integrity constraint that says a part in the Part file cannot be assigned to a facility that does not exist in the Facility file. Databases

13. DATA MANIPULATION TOOLS l VIEW - allows you to see the content of a database file, make whatever changes you want, perform simple sorting, and query to find the location of specific information. See Figure 4.7 page 137. l REPORT GENERATOR - helps you quickly define formats of reports and what information you want to see in a report. See Figures 4.8 and 4.9 page 138. DBMSs

14. DATA MANIPULATION TOOLS l QUERY-BY-EXAMPLE (QBE) TOOL - helps you graphically design the answer to a question. Figure 4.10 (page 130) shows the QBE for displaying the names and phone numbers of facility managers in charge of parts that cost more than $10. l STRUCTURED QUERY LANGUAGE (SQL) - a standardized fourth-generation language found in most database environments. SQL is the same as QBE, except that you perform a query by creating a statement instead of pointing, clicking, dragging. DBMSs

15. DATA WAREHOUSE l are a logical extension of databases l support OLAP l are among the newest and hottest buzz words and concepts in the IT field. Data Warehouses a logical collection of information - gathered from many different operational databases - that supports business analysis activities and decision-making tasks. Data warehouses...

16. DATA WAREHOUSE FEATURES l Data warehouses combine information from different databases –Making them a true repository of all an organization’s information l Data warehouses are multi-dimensional –As opposed to 2 dimensions in the relational model –Often called hypercubes (See Figure 4.23 page 148) l Data warehouses support decision making –While databases support OLTP, data warehouses support OLAP Data Warehouses

17. DATA MINING TOOLS l QUERY-AND-REPORTING TOOLS - QBE tools, SQL, and report generators. l INTELLIGENT AGENTS - various artificial intelligence tools that form the basis for “information discovery” in OLAP. l MULTIDIMENSIONAL ANALYSIS (MDA) TOOLS - slice-and-dice techniques that allow you to view multidimensional information from different perspectives. Data Warehouses the software tools you use to query information in a data warehouse.

18. IMPORTANT CONSIDERATIONS IN USING A DATA WAREHOUSE l Do you need a data warehouse? l Do you already have a data warehouse? l Who will the users be? l How up-to-date must the information be? l What data mining tools do you need? Data Warehouses

19. MANAGING THE INFORMATION RESOURCE l How will changes in technology affect organizing and managing information? l What types of database models and databases are most appropriate? l Who should oversee the organization’s information? Managing Information

20. MANAGING THE INFORMATION RESOURCE l Is information ownership a consideration? l What are the ethics involved in organizing and managing information? l How should databases and database applications be developed and maintained? Managing Information