CS403 Final Term Short Notes by VU Topper RM

Cs-403 Short Notes For Final Term: Solve By Vu_Toper-RM · All Paid Services Is Available !! · VU · Online Classes + Project · Nothing Is Impossible >> O3224021365

What is database?

Answer: 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. What is DBMS?

Redundancy is controlled. Unauthorized access is restricted. Providing multiple user interfaces. Enforcing integrity constraints. Providing backup and recovery.

QUESTION 4:

What is a Database system?

ANSWER

The database and DBMS software together is called as Database system. QUESTION 5:

Disadvantage in File Processing System?

ANSWER

Data redundancy & inconsistency. Difficult in accessing data. Data isolation. Data integrity. Concurrent access is not possible. Security Problems. . QUESTION 6:

Describe the three levels of data abstraction? ANSWER

They are three levels of

1. Physical level: The lowest level of abstraction describes how data are stored.
2. Logical level: The next higher level of abstraction, describes what data are stored in database and what relationship among those data.
3. View level: The highest level of abstraction describes only part of entire database.

QUESTION 7:

Define the "integrity rules" ANSWER

There are two Integrity rules.

Q1. Entity Integrity: States that ?Primary key cannot have NULL value?

2. Referential Integrity: States that ? Foreign Key can be either a NULL value or should be Primary Key value of other relation.

QUESTION 8: