Learn Database System
There are two main types of resources. Resources of an organization can be categorized as follows.
- People and Money
- Material and Equipment
As the operations grow in an organization it becomes difficult to manage the physical resources by observation. Therefore the managers are forced to rely on the conceptual resources. Information is a major corporate resource and must be managed using the principles that are used to manage other physical resources such as people and money.
There are two types of systems.
1. File Oriented System
The traditional approach to information system design focuses on the data processing needs of individual departments in an organization without considering the organization as a whole. Each computer application is typically designed with its own set of data files and application programs to meet the information requirements of a particular department or a user group.
2. Database Systems
An information system that uses the database instead of data files. It consists of a Database, Database Management System, Data dictionary, appropriate Hardware, Software, and people. Database systems can be designed to store large data collection and centralized data structure. So it supports the overcomes the limitations of the file-oriented system.
Comparison of File Processing System with Database Systems
|Traditional File Approach||Database Approach|
|Use separate data files for every application||All applications share a pool of connected and integrated data|
|High Data Redundancy||Minimal Data Redundancy|
|Data inconsistency||Data Consistency|
|Data not shareable||Data shareable|
|Data dependence||Data independence|
|There is no centralized control for overall data in different files||There is a centralized control for overall data in the database|
|Data Isolation||Data Integration|
|Difficult to access||Easy to access|
The disadvantage of having a database
- Complexity and size
- Cost of DBMS and additional hardware costs
- Performance problem
- Higher impact of a failure
Components of a database system
There are four main components of the Database system. Such as
In a database, there are a set of physical devices resides. It consists of one or additional computers, disk drives, printers, connecting cables, and other auxiliary and connecting hardware.
There are two sorts of database software.
- General-purpose database management software
A general-purpose database system usually called the database management system. DBMS is a system package that allows users to create and maintain an information database and also it gives the user to produce controlled access to this database.
- Application software
DBMS facilities manipulate the database and that is used by Application Software to achieve a specific business function. Application software is generally written using standard programming languages or it may be written in a fourth-generation language. These programs utilize the command language of the DBMS and make use of the information contained in the data dictionary.
Two different types of people (users and practitioners) are concerned with the database.
Who needs information from the database to carry out their primary business responsibility
eg: executive managers staff clerical personnel
People liable for the database system and its associated application software.
eg: database administrator, analysts, programmers, database and system designers, information systems managers.
A database must contain correct and valid data to provide the right information to the right people at the right time to perform business tasks.
Functions of DBMS
1. Data Security
The database is a valuable resource for needing protection. The DBMS provides database security by limiting access to the database to authorized personnel. Authorized users will generally be restricted to the particular data they can access and whether they can update it. Access is often controlled by a password and by the data views, which are definitions of restricted portions of the database.
2. Data Integrity
The integrity and consistency of the database are protected via constraints on values that data items can have and by backup and recovery capabilities provided by the DBMS. Data constraint definitions are maintained in the dictionary.
3. Backup and Recovery
Supported by software that automatically logs changes to the database and provides a means of recovering the current state of the database in case of system failure.
4. Concurrent Data Access
One of the chief functions of the DBMS is to support the access, retrieval, and update of data in the database. The DBMS provides the physical mechanisms permitting multiple users to access a spread of connected information quickly and with efficiency.
5. User-Oriented Data Manipulation
DBMS provides user-oriented data manipulation tools. Easy-to-use question languages permit users to formulate queries and request one-time reports directly from the DB. Often query languages can contain facilities to format the results of queries as reports.
6. Application Development
The DBMS software unremarkably provides important help to the appliance engineer. Tools for the screen, menu and report generation, application generators, compilers, data, and view definition facilities.
1. Personal Computer Databases
Design to support one user with a stand-alone PC. Eg: a salesperson keeping track of his customer information with contact details.
2. Workgroup Databases
A relatively small group (less than 25 people), who are collaborating on the same project or application. Ex: a software development team maintains a list of software objects.
3. Department Databases
A department is a functional unit of an organization. It is larger than a workgroup. Department databases are designed to support the various functions and activities of one department.
Ex: a personal database that is designed to track data concerning employees, jobs, skills, and job assignments.
4. Enterprise Databases
An enterprise is one whose scope is the entire organization or enterprise. Such databases area unit meant to support organization-wide operations and deciding.
Ex: a large healthcare organization that operates a group of medical centers. Enterprise info will support info wants from several departments. The most important type of enterprise database is called a data warehouse.
What is Next?
In the next lesson, you will learn the Relational Data Model of the Database system.
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