Database Management System (DBMS)
Introduction:
A "Database" is a collection of related information stored related data. The database managed by a software package known as Database Management System. A set of computer program used to control the reading and writing of data from database called DBMS. Some commonly used DBMS are Database III +, Ms-Access, Ms-SQL and Oracle etc.
So, in short we may say that a DBMS is a combined set of hardware and software that can be used to setup and monitor database.
A "Database" is a collection of related information stored related data. The database managed by a software package known as Database Management System. A set of computer program used to control the reading and writing of data from database called DBMS. Some commonly used DBMS are Database III +, Ms-Access, Ms-SQL and Oracle etc.
So, in short we may say that a DBMS is a combined set of hardware and software that can be used to setup and monitor database.
RDBMS (Relational Database Management System)
A type of database management System that stores data in the form of related tables is known as RDBMS. In the RDBMS, In the RDBMS data are stored in different tables having similar attributes and suitable relation is established between various tables of identical field.
A type of database management System that stores data in the form of related tables is known as RDBMS. In the RDBMS, In the RDBMS data are stored in different tables having similar attributes and suitable relation is established between various tables of identical field.
Types of database:
There are two types of database on the basis of their functionality and location, which are following.
There are two types of database on the basis of their functionality and location, which are following.
1.) Centralized Database
2.) Distributed Database
2.) Distributed Database
Centralized Database
In centralized method there is one central computer facility, which provides computer services to all the users. All the program run on a main host computer, including the DBMS, the computer, including the DBMS, the application that access the database and the communication facilities that send and receive data from the User's terminals. So, such type of database works on client-server networking. The controlling mechanism is also centralized and data are deposited in a central location.
In centralized method there is one central computer facility, which provides computer services to all the users. All the program run on a main host computer, including the DBMS, the computer, including the DBMS, the application that access the database and the communication facilities that send and receive data from the User's terminals. So, such type of database works on client-server networking. The controlling mechanism is also centralized and data are deposited in a central location.
Advantage:
1. It reduces duplication of record.
2. The computer specialist work as a group.
3. Data processing produce become more professional and it has better supervision control.
1. It reduces duplication of record.
2. The computer specialist work as a group.
3. Data processing produce become more professional and it has better supervision control.
Disadvantage:
1. It is difficult to access each user.
2. The computer staff is required to service the entire department.
2. The computer staff is required to service the entire department.
Distributed Database
In the distributed method there are independent computer facilities for each department but there is also central facility to control and co-ordinate the activity of each. So, distributed database is a database where several computers on a network each store part of data, which can be accessed by any of the computer.
In the distributed method there are independent computer facilities for each department but there is also central facility to control and co-ordinate the activity of each. So, distributed database is a database where several computers on a network each store part of data, which can be accessed by any of the computer.
Advantage:
1. Each department need can be met on an individual basis
2. It is relatively easy to access.
1. Each department need can be met on an individual basis
2. It is relatively easy to access.
Disadvantage:
1. For the implementation of distributed database, it is required sophisticated hardware and software control.
Each personnel of the department should have knowledge about computer system.
1. For the implementation of distributed database, it is required sophisticated hardware and software control.
Each personnel of the department should have knowledge about computer system.
Question: Who is DBA? Explain the major role of DBA in the database environment.
Answer: The Person who is responsible for database handling in the organization is known as DBA (Database Administrator). DBA has authority and responsibility for database maintaining like editing, deleting, entering etc. He must have sound knowledge of the structure of the database and DBMS. The DBA has many different responsibilities, but the overall goal of the DBA is to keep the server up at all times and to provide user with access to the required information when they need.
The DBA should have following attributes:
Answer: The Person who is responsible for database handling in the organization is known as DBA (Database Administrator). DBA has authority and responsibility for database maintaining like editing, deleting, entering etc. He must have sound knowledge of the structure of the database and DBMS. The DBA has many different responsibilities, but the overall goal of the DBA is to keep the server up at all times and to provide user with access to the required information when they need.
The DBA should have following attributes:
1. A DBA should know the type of data coding mechanism method or removing – non relevant data, platform required for processing, inter-relationship among database (RDBMS), Type of information to be processed.
2. Knowledge of SQL.
Knowledge of operation system in which database server is running.
Knowledge of operation system in which database server is running.
3. Knowledge about database server
4. Sound database design
5. Knowledge about networking
Role of DBA
1. DBA is responsible for data security so he must follow the data security law & methods.
2. DBA has to collect and maintain data in the meaningful way so that data can be changed into information.
3. DBA has to provide data information to the decision maker.
4. DBA should design database according to the needs of the organization.
5. DBA is responsible to supervise the adding of new data.
6. DBA is responsible for the data dictionary
7. DBA is responsible for the documentation
8. DBA is responsible for ensuring that the data in the database meets the information needs of the organization
9. Installing and upgrading the database server
Managing database users & security.
Managing database users & security.
What do you understand by data security? Explain the method of data security normally adopted by the organization?
Answer: Security refers to safely against attack or failure. Data security means to protect and preserve data program against intentional damage, modification by unauthorized person. In the wide concept, security covers overall physical security such as file protection, smoke, dust, heat, power supply on well as software and hardware security. One important aspect of control is the control data to prevent its loss, misuse or disclosure. This type of control is called "data security". So, data security refers to the protection of data, preventing the misuse of data or unauthorized access to data for internal modification, access control to the unauthorized person to the database.
Necessary security method should be applied for the protection of data in the computer system. Following are the common methods through which we can secure data.
1. The use of backup copies of tapes, disk and CD-ROM i.e. using regular Backup system of data we can secure from accidental loss.
2. Making physical prevention.
a.) Using UPS to supply regular power supply
b.) Keeping data under lock & key
c.) Using backup system to save accidental loss of data. Such as hardware failure, software crashes
d.) Using password login system to prevent unauthorized use of computer terminal
e.) Virus can damage data and program so data program should be protected from virus. We can protect our data from virus through
f.) Using PDC (Primary domain control) & BDC (Backup domain Control) in networking system
g.) Constant checks of security
h.) Don't use pirated software
i.) Maintaining central data control system
j.) Filling and updating hard-copy printing regularly of the most important & valuable data from the database.
k.) Maintain properly the access control over data and so that only authorized user are allowed to access i.e. user logic process as password system to be maintained.
=0=
No comments:
Post a Comment