SS 2 WEEK THREE LESSON NOTE

 

Ss2

TOPIC: DATABASE II

Introduction

In this lesson we shall take a look at Advantages, disadvantages and Terminologies of Database Management Systems.

Advantages of DBMS

a)     Improved availability: one of the principle advantages of a DBMS is that the same information can be made available to different users.

b)     Minimized redundancy: the data in DBMS is more concise because as a general rule, the information in it appears just once. This reduces data redundancy, or in other words the need to repeat data over and over again.

c)     Accuracy: Accurate, consistent, and up-to-date data is a sign of data integrity. DBMS foster data integrity because updates and changes to the data only have to be made in one place.

d)     Program and file consistency: using a DBMS, file formats and system programs are standardized. This makes data files easier to maintain because the same rules and guidelines apply across all types of data.

e)     User-friendly: data is easier to access and manipulate with a DBMS than without it. In most cases, DBMS also reduce the reliance of individual users on computer specialists to meet their data needs.

f)       Improved security: as stated earlier, DBMS allow multiple users to access the same data resources. This capability is generally viewed as  a benefit, but there are potential risks for the organization.

Disadvantages of DBMS

a)     Cost: implementing a DBMS can be expensive and time-consuming, especially in large organizations. Training alone can be quite costly.

b)    Security: even with safeguards in place, it may be possible for some unauthorized users to access the database.

Basic Database Terminologies

a)     Field: a filed contains an item of data; that is, a character, or group of characters that are related.

b)     Character: a character is the most basic element of data that can be observed and manipulated. A character is a single symbol such as a digit, letter, or other special character e.g. $, #, @

c)     Record: a record is composed of a group of related fields. As another way of saying it, a record contains a collection of attributes related to an entity such as a person or product.

d)     Key: in order to track and analyze data effectively, each record requires a unique identifier or what is called a key.

e)     Database file: a database file is defined as a collection of related records. A database file is sometimes called a Table.


 ASSESMENT

Difference between Database and file system

 

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