DATABASE MANAGEMENT SYSTEMS
MCA II YEAR II SEMESTER
Mrs. K .URMILA, MCA.,
DEPARTMENT OF COMPUTER APPICATIONS
CHADALAWADA RAMANAMMA ENGINEERING COLLEGE
CHADALAWADA NAGAR, RENIGUNTA ROAD, TIRUPATI (A.P) - 517506
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.
The process of converting the data (raw facts) into meaningful information is called as
Note: In business processing knowledge is more useful to make decisions for any organization.
CREC. Dept. of MCA
DIFFERENCE BETWEEN DATA AND INFORMATION:
2. It is in unorganized form
3. Data doesn’t help
2. It is in organized form
in 3. Informationhelpsin
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
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
Goals, Properties and Need of DBMS, Database Users & DBA, Levels of Abstraction in DBMS, 3 Schema Architecture, Data Independence, Database system Structure, Storage Manager Components, Application Architecture, Database Design, DBMS Functions
System Failure classifications, Undo Logging, Log Records, Redo Logging, Undo/Redo Logging, Protecting Against Media Failures, Recovery Using Archive and Log, Terminologies, Serializability, Concurrency control Techniques, Two phase Locking Protocol, Cascading Schedule, Timestamps