SSS TWO WEEK TWO LESSON NOTE (ICT_223)

 

Ss2

TOPIC:  HANDLING COMPUTER FILES

Introduction

File operation deals with the physical movement of data in and out of files. User programs effectively use file operations through appropriate programming language syntax. The file management system manages the independent files and acts as the software interfaces between the user programs and file operations.

Basic Operations of Computer Files

1.    Insertion: records must be inserted at the place dictated by the sequence of the keys. As  obvious, direct insertion into the main data file would  lead to frequent rebuilding of the file. This problem could be mitigated by reserving overflow areas in the file for insertions. But this leads to wastage of space and also the overflow areas may also be filled.

2.    Deletion: deletion is the reverse of insertion. The space occupied by the record should be free for use.

3.    Updating: updating is a combination of insertion and deletion. The record with new values is inserted and the earlier version deleted.

4.    Retrieval: user programs will often retrieve data for viewing prior to making decisions therefore it is vital that data reflects the latest state of the data if the merging activity has not taken place.

File security

File security is a feature of your file system which controls which user can access which file and place limitations on what users can do to files. File security consists of two key elements: authentication and permission. Authentication is how the computer finds out who you are when you provide username and password. Permissions are the properties of a file or fields that specify who can access it.


Differences between computer files and manual files

Computer files

Manual files

1. computer files are easily assessable

Manual files are not easily assessable

2. computer files are environmentally friendly

Manual files are not environmentally friendly

3. computerized filling system can store huge number of documents in a tiny fraction of space

Manual files require lots of space for storing huge number of documents

4. files in a computer system can be encrypted to render them unreadable by those without permission.

Manual files cannot be encrypted

5. copies of computerized files can easily be created and stored in various location.

A lot of time is required in creating copies of documents

 

 

 

 

 

Comments

Post a Comment

Popular posts from this blog

JSS 2 WEEK TWO LESSON NOTE_FIRST TERM 2023

Image
  Jss2 TOPIC: CLASSIFICATION OF COMPUTER BY GENERATION OBJECTIVE At the end of this topic you should be able to:  1. List the criteria for classifying computers.          I.                   2. State the features of computers classified based on technological age. Introduction Computers can be classified into different categories based on different criteria. Basically, computers can be classified based on the following criteria: 1.      Size. 2.      Types 3.      Generation 4.      Purpose or versatility Based on the technological Age of the computer, computers can be classified into: ·         First generation ·         Second generation ·         Th...
Read more

JSS ONE WEEK THREE LESSON NOTE (ICT_223)

Image
  Jss1 TOPIC:   MASTERY OF THE KEYBOARD Introduction A computer keyboard is the most commonly used input device. It is defined as the set of typewriter-like keys that enables you to enter data into a computer or other devices. Computer keyboard are similar to electric-typewriters but contain additional typing keys. The standard arrangement of alphabetic keys on the keyboard is known as the QWERTY. The computer keyboard could be wired or wireless. Types of keyboard There are different types of keyboard depending on what they are used for. Some have more keys than the others. Keyboards also come in different shapes but basically a keyboard has regular shape. The types of keyboards are: a)      Enhanced keyboard b)     Standard keyboard   c)      Windows keyboard d)     AT keyboard   Sections of the Keyboard The keyboard is divided into the following sections: ...
Read more