Friday, February 10, 2017

Computer Science Questions and Answers: Information Systems and Database Operations (Files and File organization) Part - 16

1. What is database?
A database is a collection of logically related data

2. What are the File Operations?
The following are the types of file operations required to process records stored in the files.
1. File creation
2. Location a record
3. Adding a record
4. Deleting a record
5. Modifying a record

Types of Files:
  • Master file
  • Transaction file
3. Write the difference between Master file and Transaction File 
a. Master file 
1) The data stored in these files are permanent by nature
2) This file is empty while nature 
3)This files are updated only through recent transactions
4) This file stores large amount of data Eg: customer ledgers, student database

b. Transaction File 
1) The data stored in these files are temporary by nature
2) This file contains data only for period of time and send to the master file
3) Any data to be modified is done in this file
4) In this file the data to be modified is stored . Eg: price of the products, customers order for the products, inserting new data to the database etc.

File Organisation:
It refers to the way of arranging the records in a file which can be accessed in a faster way. The criteria considered in choosing a file organization are:
1) Fast access to single record or collection of related records.
2) Easy record adding/ update/ removal without disrupting.
3) Storage efficiency
4) Redundancy as a warranty against data corruption.

The files are generally viewed as
  • Logical File organization: The groups of fields which are combined to form logical record, which can perform different operations on the file.
  • Physical file organization: The data which is stored in the form of records can be placed in any storage devices, main memory, secondary memory etc.