Note for Database Management System - DBMS By Charanjeev Singh

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LECTURE NOTES ON DATABASE MANAGEMENT SYSTEMS MCA II YEAR II SEMESTER (JNTUA-R09) Mrs. K .URMILA, MCA., Assistant Professor DEPARTMENT OF COMPUTER APPICATIONS CHADALAWADA RAMANAMMA ENGINEERING COLLEGE CHADALAWADA NAGAR, RENIGUNTA ROAD, TIRUPATI (A.P) - 517506

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UNIT -1 CREC. Dept. of MCA Page 4

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UNIT -1 The Worlds of Database Systems INTRODUCTION TO BASIC CONCEPTS OF DATABASE SYSTEMS: What is Data? The raw facts are called as data. The word “raw” indicates that they have not been processed. Ex: For example 89 is the data. What is information? The processed data is known as information. Ex: Marks: 89; then it becomes information. What is Knowledge? 1. Knowledge refers to the practical use of information. 2. Knowledge necessarily involves a personal experience. DATA/INFORMATION PROCESSING: The process of converting the data (raw facts) into meaningful information is called as data/information processing. When Data When Information Processed Knowledge Processed Note: In business processing knowledge is more useful to make decisions for any organization. CREC. Dept. of MCA Page 5

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DIFFERENCE BETWEEN DATA AND INFORMATION: DATA 1.Raw facts 2. It is in unorganized form 3. Data doesn’t help decision making process INFORMATION 1.Processed data 2. It is in organized form in 3. Informationhelpsin decision making process FILE ORIENTED APPROACH: The earliest business computer systems were used to process business records and produce information. They were generally faster and more accurate than equivalent manual systems. These systems stored groups of records in separate files, and so they were called file processing systems. 1. File system is a collection of data. Any management with the file system, user has to write the procedures 2. File system gives the details of the data representation and Storage of data. 3. In File system storing and retrieving of data cannot be done efficiently. 4. Concurrent access to the data in the file system has many problems like a Reading the file while other deleting some information, updating some information 5. File system doesn’t provide crash recovery mechanism. Eg. While we are entering some data into the file if System crashes then content of the file is lost. 6. Protecting a file under file system is very difficult. The typical file-oriented system is supported by a conventional operating system. Permanent records are stored in various files and a number of different application programs are written to extract records from and add records to the appropriate files. CREC. Dept. of MCA Page 6