Data Environments

Chapter I

Define each of the following terms in your own word

a) Database

b) DBMS

c) Metadata

a) Database (Crucial Concept): A database is essentially a means of storage and retrieval of items of data. The data is usually either numerical or textual, although other data forms can be accommodated.

A database is a collection of data held logically and with a purpose. Is designed and organized in such manner that it can be accessed later on for different purposes. For example we need to access our Database to update some information from it or just to extract it. Most of the businesses need a DB. They need to retrieve data in its complete form for further analysis or different objectives. Databases are needed to store our data being ready and available when required.

b) DBMS (Crucial Concept): The DBMS would be responsible for all database activities (storage, retrieval, indexing, etc) and also be responsible for keeping a detailed description of the data being held.

DBMS is a program that helps users to communicate with the Operating System through an interface in order to access the data from a Database in a friendly way and as soon as possible. It allows users to store retrieve and update information quick and productive. DBMS handle to recover the database in case of system error and needs to have an organized system for security issues.

c) Metadata – Data that Describes Data

Metadata it’s all about data being held in a Database. There is no clear definition about this. I prefer to say that is the data or information contained in a DB.

Chapter II

List and briefly describe each of the four main components of a modern database system.

The four main components of a DB system are:

a) Data

b) Hardware

c) Software

d) Users

a) Data – Information that is stored in the DB. Some of the systems can have single-user in which at most one user can access the DB at any given time or multi-user in which many users can access the DB at the same time. Data in a DB system can be Integrated or Shared. Integrated is when a DB contains more files with any redundancy between those files partly eliminated. Shared is when data in the DB can be shared between users in the same time for different purposes.