Introduction To Database PDF

Introduction to Database TMF2034 Database Concept and Design Prepared by Bong Chih How 1  By the end of the class, the student is able To describe data,...

Introduction to Database TMF2034 Database Concept and Design Prepared by Bong Chih How 1  By the end of the class, the student is able To describe data, information Objectives To describe database and database management system To appreciate the database evolution from file systems 2 TMF2034 Database Concept and Design Prepared by Bong Chih How  Data vs Information TMF2034 Database Concept and Design Prepared by Bong Chih How 3  Raw data - Not yet Data (singular or plural) been processed to are raw facts reveal the meaning Data vs. Building blocks of Raw data must be formatted for storage, Information information processing, and presentation Data are the foundation of information, which is the bedrock of knowledge 4 TMF2034 Database Concept and Design Prepared by Bong Chih How  Information Information used to Accurate, relevant, produced by reveal meaning in timely information processing data data is the key to good Data vs. decision making Information (cont’d.) Good decision Data management: focuses on making is the key to proper generation, storage, and organizational retrieval of data survival TMF2034 Database Concept and Design Prepared by Bong Chih How Data or Information? Data or Information? 7  Good decisions require good information derived from raw facts Data is managed most efficiently when stored in a database Databases solve many of the problems Why do I encountered in data management Used in almost all modern settings care about involving data management: databases? Business Research Administration Important to understand how databases work and interact with other applications TMF2034 Database Concept and Design Prepared by Bong Chih How What is a database? TMF2034 Database Concept and Design Prepared by Bong Chih How 9  A database is a collection of organized data which are collected over time. The data contains both structured user data and metadata. User data: raw facts of interest to end user They are student names, grades, salary etc. Metadata: data about data They are data type, relationship, date What is created, data modified, file size, etc. E.g. Customer: ID, name, address, etc a Database? Metadata also known as system catalog and data dictionary Database management system (DBMS) Is a collection of software Manages the database structure Controls access to data stored in the database More on this later TMF2034 Database Concept and Design Prepared by Bong Chih How  11 Database Management System TMF2034 Database Concept and Design Prepared by Bong Chih How  An integrated database environment DBMS controls the access to the databases DBMS eliminates most of file system’s problems Current generation DBMS software What is a Database Stores data structures, relationships between Management structures, and access paths System Defines, stores, and manages all access paths (DBMS)? and components Logically related data stored in a single logical data repository Physically distributed among multiple storage facilities TMF2034 Database Concept and Design Prepared by Bong Chih How 12 13 Role of the DBMS 1 2 3 Serve data to end user Allow writing Allow designing, creating Interact DBMS directly or applications for other and maintaining the indirectly users database with ease Use SQL to retrieve the Java, C, C++, C# … Carry out the task by data from the DBMS database administrator (DBA) TMF2034 Database Concept and Design Prepared by Bong Chih How 14 A Database System 15 Advantages of Database Systems (1) Allow sharing of data Control of redundancy Ensure data consistency Improve data standards More control over concurrency 16 Data redundancy Data redundancy exists when unnecessarily duplicated data are found in the database. 17  Data inconsistency Data inconsistency exists when different and conflicting versions of the same data appear in different places. 18 Advantages of Database Systems (2) Better data security Improved data integrity Better backup and recovery procedures Fast development of new applications Better data accessibility 19 Disadvantages of Database Systems Increased costs Management complexity Maintaining currency Vendor dependence Frequent upgrade/replacement cycles 20  File Systems and Databases TMF2034 Database Concept and Design Prepared by Bong Chih How 21 A Simple Database Everyone Can Do – Flat File 22  When data grow, processing may be difficult A dedicated program may create to read the flat file database Flat file Read line by line, fields are separated using a separator However, flat file database is subjected to structural, data dependence and data redundancy. TMF2034 Database Concept and Design Prepared by Bong Chih How  A Manual File System TMF2034 Database Concept and Design Prepared by Bong Chih How 24  Contents of each file folder are logically related Manual File Served as a data repository for small Systems data collections Cumbersome for large collections TMF2034 Database Concept and Design Prepared by Bong Chih How 25 Computerized File Systems (1) Data processing (DP) specialist converted computer file structure from manual system Wrote software that Designed the managed the data application programs Computer file systems resembled manual systems 26 Computerized File Systems (2) TMF2034 Database Concept and Design Prepared by Bong Chih How Computerized File Systems (3) 28 A Simple File System in an Organization  Each file – owned by individual/department. A Simple File System in an Organization Islands of Information Problem A scenario where the information cannot be shared easily from one large system to another in a timely or effective way 31 Contrasting Database and File Systems File System Redux: Spreadsheet Ubiquitous use of personal productivity tools can introduce the same problems as the old file systems Widely used by business users Users have become so adept at working Microsoft Excel with spreadsheets, they tend to use them to complete tasks for which spreadsheets are not appropriate – database substitute TMF2034 Database Concept and Design Prepared by Bong Chih How 34  Lengthy development times Problems Difficulty of getting quick answers with File System Complex system administration Data Processing Lack of security and limited data sharing Extensive programming 36 Preparing for Your Database Professional Career 37  An ice-cream store Which is the A tuition center following A computer hardware and repair store businesses A pharmacy require A car spare-part store database? A florist store A Real estate corporation A clinic A second hand car dealer A furniture store TMF2034 Database Concept and Design Prepared by Bong Chih How 38 Tutorial 1 : Introduction to Database Relax & watch video https://www.youtube.com/watch?v= bitUrAmXTnI&t=9s TMF2034 Database Concept and Design Prepared by Bong Chih How 39  Tutorial 1 : Introduction to Database Question 1 Data vs. information? Question 2 Give examples TMF2034 Database Concept and Design Prepared by Bong Chih How 40  Question 3 Question 4 DBMS vs Why do you Tutorial 1 : Computerized need Introduction to file systems database Database systems? 41