1. What is database?
A database is a logically coherent collection of data with some inherent meaning, representing some aspect of real world and which is designed, built and populated with data for a specific purpose.
2. What is DBMS?
It is a collection of programs that enables user to create and maintain a database. In other words it is general-purpose software that provides the users with the processes of defining, constructing and manipulating the database for various applications.
3. What is a Database system?
The database and DBMS software together is called as Database system.
4. Advantages of DBMS?
? Redundancy is controlled.
? Unauthorised access is restricted.
? Providing multiple user interfaces.
? Enforcing integrity constraints.
? Providing backup and recovery.
5. Disadvantage in File Processing System?
? Data redundancy & inconsistency.
? Difficult in accessing data.
? Data isolation.
? Data integrity.
? Concurrent access is not possible.
? Security Problems.
6. Describe the three levels of data abstraction?
The are three levels of abstraction:
? Physical level: The lowest level of abstraction describes how data are stored.
? Logical level: The next higher level of abstraction, describes what data are stored in database and what relationship among those data.
? View level: The highest level of abstraction describes only part of entire database.
7. Define the "integrity rules"
There are two Integrity rules.
? Entity Integrity: States that “Primary key cannot have NULL value”
? Referential Integrity: States that “Foreign Key can be either a NULL value or should be Primary Key value of other relation.
8. What is extension and intension?
Extension -
It is the number of tuples present in a table at any instance. This is time dependent.
Intension -
It is a constant value that gives the name, structure of table and the constraints laid on it.
9. What is System R? What are its two major subsystems?
System R was designed and developed over a period of 1974-79 at IBM San Jose Research Center. It is a prototype and its purpose was to demonstrate that it is possible to build a Relational System that can be used in a real life environment to solve real life problems, with performance at least comparable to that of existing system.
Its two subsystems are
? Research Storage
? System Relational Data System.
10. How is the data structure of System R different from the relational structure?
Unlike Relational systems in System R
? Domains are not supported
? Enforcement of candidate key uniqueness is optional
? Enforcement of entity integrity is optional
? Referential integrity is not enforced
Read More Questions:
RDBMS Interview Questions Part1
RDBMS Interview Questions Part2
RDBMS Interview Questions Part3
RDBMS Interview Questions Part4
RDBMS Interview Questions Part5
A database is a logically coherent collection of data with some inherent meaning, representing some aspect of real world and which is designed, built and populated with data for a specific purpose.
2. What is DBMS?
It is a collection of programs that enables user to create and maintain a database. In other words it is general-purpose software that provides the users with the processes of defining, constructing and manipulating the database for various applications.
3. What is a Database system?
The database and DBMS software together is called as Database system.
4. Advantages of DBMS?
? Redundancy is controlled.
? Unauthorised access is restricted.
? Providing multiple user interfaces.
? Enforcing integrity constraints.
? Providing backup and recovery.
5. Disadvantage in File Processing System?
? Data redundancy & inconsistency.
? Difficult in accessing data.
? Data isolation.
? Data integrity.
? Concurrent access is not possible.
? Security Problems.
6. Describe the three levels of data abstraction?
The are three levels of abstraction:
? Physical level: The lowest level of abstraction describes how data are stored.
? Logical level: The next higher level of abstraction, describes what data are stored in database and what relationship among those data.
? View level: The highest level of abstraction describes only part of entire database.
7. Define the "integrity rules"
There are two Integrity rules.
? Entity Integrity: States that “Primary key cannot have NULL value”
? Referential Integrity: States that “Foreign Key can be either a NULL value or should be Primary Key value of other relation.
8. What is extension and intension?
Extension -
It is the number of tuples present in a table at any instance. This is time dependent.
Intension -
It is a constant value that gives the name, structure of table and the constraints laid on it.
9. What is System R? What are its two major subsystems?
System R was designed and developed over a period of 1974-79 at IBM San Jose Research Center. It is a prototype and its purpose was to demonstrate that it is possible to build a Relational System that can be used in a real life environment to solve real life problems, with performance at least comparable to that of existing system.
Its two subsystems are
? Research Storage
? System Relational Data System.
10. How is the data structure of System R different from the relational structure?
Unlike Relational systems in System R
? Domains are not supported
? Enforcement of candidate key uniqueness is optional
? Enforcement of entity integrity is optional
? Referential integrity is not enforced
Read More Questions:
RDBMS Interview Questions Part1
RDBMS Interview Questions Part2
RDBMS Interview Questions Part3
RDBMS Interview Questions Part4
RDBMS Interview Questions Part5
No comments:
Post a Comment