1 January

Management of Information Technology Chapter 10 Database Management Asst. Prof. Wichai Bunchua

1 January 3 Data Management Without data and the ability to process it, an organization could not successfully complete most business activities Data consists of raw facts To transform data into useful information it must first be organized in a meaningful way

1 January Purpose: To organize and keep track of things Spreadsheets Keep track of only a single theme   Example: Student test scores in a course Databases Allow keeping track of multiple themes   Examples: Student grades, office visits, student 5-4 What Is the Purpose of a Database?

1 January 5-5 A List of Student Grades, Single Theme

1 January 5-6 Form for Recording Multiple Themes

1 January 7 What Is a Database? Table or file: A group of records

1 January 5-8 Hierarchy of Data Elements

1 January Components of a Database 5-9 Components of a Database

1 January First row of the Table is related to Andrea Baker in Student Table Last row in Office_Visit Table related to Adam Verberra in Student Table 5-10 Example of Relationships Among Rows

1 January A column or group of columns that identifies a unique row in a table. Student Number is key of Student table. Every table must have a key. Sometimes more than one column is needed to form a unique identifier. In a table called City, key would consist of combination of City and State columns. _Num is key of Table. VisitID is key of Office_Visit Table. Key 5-11 Special Terms

1 January A non-primary key in one table that is related to a primary key of a different table Foreign key Relationships among tables are created by using foreign keys Relationa l database s Formal name for a table Relation 5-12 More Special Terms

1 January 5-13 Metadata: Data that Describes Data

1 January The Database Approach The Database Approach Traditional approach to data management Separate data files are created and stored for each application program Database approach to data management Pool of related data is shared by multiple application programs

1 January The Database Approach to Data management The Database Approach to Data management

1 January Disadvantages of the Database Approach Disadvantages of the Database Approach

1 January Data Modeling and Database Characteristics When building a database, an organization must consider: Content: What data should be collected and at what cost? Access: What data should be provided to which users and when? Logical structure: How should data be arranged so that it makes sense to a given user? Physical organization: Where should data be physically located?

1 January Data Modeling Building a database requires two types of designs Logical design Abstract model of how data should be structured and arranged to meet an organization’s information needs Physical design Starts from the logical database design and fine-tunes it for performance and cost considerations

1 January Data Modeling (continued) Data model Diagram of data entities and their relationships Enterprise data modeling Starts by investigating the general data and information needs of the organization at the strategic level Entity-relationship (ER) diagrams Data models that use basic graphical symbols to show the organization of and relationships between data

1 January Data Modeling (continued)

1 January The Relational Database Model Relational model Describes data using a standard tabular format Each row of a table represents a data entity Columns of the table represent attributes Domain Allowable values for data attributes

1 January The Relational Database Model

1 January RelationshipRelationship ตารางที่มีข้อมูลเกี่ยวข้องกัน สามารถสร้างความสัมพันธ์ เพื่อลดความซ้ำซ้อนของ ข้อมูล และสะดวกต่อการ แก้ไขข้อมูล

1 January The Relational Database Model (continued) Manipulating Data Selecting Eliminates rows according to certain criteria Projecting Eliminates columns in a table Joining Combines two or more tables Linking Manipulating two or more tables that share at least one common data attribute

1 January The Relational Database Model (continued) Data cleanup Process of looking for and fixing inconsistencies to ensure that data is accurate and complete Eliminates redundancies and anomalies

1 January Database Management Systems (DBMSs) Creating and implementing the right database system Ensures that the database will support both business activities and goals Capabilities and types of database systems vary considerably

1 January Overview of Database Types Flat file Simple database program whose records have no relationship to one another Single user Only one person can use the database at a time Examples: Access, FileMaker, and InfoPath Multiple user Allows dozens or hundreds of people to access the same database system at the same time Examples: Oracle, Sybase, and IBM

1 January Creating and Modifying the Database Data definition language (DDL) Collection of instructions and commands used to define and describe data and relationships in a specific database Allows database’s creator to describe data and relationships that are to be contained in the schema Data dictionary Detailed description of all the data used in the database

1 January Storing and Retrieving Data When an application program needs data It requests the data through the DBMS Concurrency control Can be used to avoid this potential problem

1 January Storing and Retrieving Data

1 January Manipulating Data and Generating Reports Data manipulation language (DML) Commands that 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

1 January International standard language for creating databases and database structures, and processing databases All five of the most popular DBMS products accept and process SQL SQL “see-quell” INSERT INTO Student ([Student Number], [Student Name], HW1, HW2, MidTerm) VALUES (1000, ’Franklin, Benjamin’, 90, 95, 100); SQL statement to insert a new row into student table: 5-32 Structured Query Language (SQL)

1 January Database Administration DBA Works with users to decide the content of the database Works with programmers as they build applications to ensure that their programs comply with database management system standards and conventions Data administrator Responsible for defining and implementing consistent principles for a variety of data issues

1 January Process large organizational and workgroup databases Support many users and many database applications Support 24/7 operations; manage databases that span dozens of disks with hundreds of gigabytes or more of data IBM’s DB2, Microsoft’s SQL Server, and Oracle’s Oracle 11g Enterprise DBMS Designed for smaller, simpler database applications Used by single user or small workgroup of fewer than 100 users, but normally fewer than 15 Personal DBMS Enterprise DBMS vs. Personal DBMS 5-34

1 January Selecting a Database Management System Important characteristics of databases to consider Database size Database cost Concurrent users Performance Integration Vendor

1 January Database Applications Today’s database applications manipulate the content of a database to produce useful information Common manipulations Searching, filtering, synthesizing, and assimilating data contained in a database using a number of database applications

1 January 5-37 Database Applications

1 January Linking Databases to the Internet Semantic Web Developing a seamless integration of traditional databases with the Internet Allows people to access and manipulate a number of traditional databases at the same time through the Internet

1 January Four Database Application Programs Running on a Web Server Computer 5-39

1 January Data Warehouses, Data Marts, and Data Mining Data warehouse Database that holds business information from many sources in the enterprise Data mart Subset of a data warehouse Data mining Information-analysis tool that involves the automated discovery of patterns and relationships in a data warehouse

1 January Elements of a Data Warehouses

1 January Distributed Databases Distributed database Database in which the data may be spread across several smaller databases connected via telecommunications devices Gives corporations more flexibility in how databases are organized and used Replicated database Holds a duplicate set of frequently used data

1 January Principles of Information Systems, Ninth Edition43 The Use of a Distributed Databases

1 January Online Analytical Processing (OLAP) Software that allows users to explore data from a number of different perspectives Leading OLAP software vendors Microsoft, Cognos, SAP, Business Objects MicroStrategy, Applix, Infor, and Oracle

1 January Summary Data One of the most valuable resources that a firm possesses Entity Generalized class of objects for which data is collected, stored, and maintained Traditional file-oriented applications Often characterized by program-data dependence Relational model Places data in two-dimensional tables

1 January Summary (continued) DBMS Group of programs used as an interface between a database and its users and other application programs Basic functions Providing user views Creating and modifying the database Storing and retrieving data Manipulating data and generating reports

1 January Summary (continued) Data warehouses Relational database management systems specifically designed to support management decision making Data mining Automated discovery of patterns and relationships in a data warehouse Business intelligence Process of getting enough of the right information in a timely manner and usable form

1 January Questions?Questions?

1 January Assignment#10Assignment#10 10 a. Database, Database management system (DBMS) และ Database administrator (DBA) คืออะไร ต่างกัน อย่างไร 10 b. จงอธิบายคำ Data Entities, Attributes, Data Elements และ Keys

1 January ส วั ส ดี