Session 1 – Appreciate Concept of Database Management System – 50+ Question Answer
21. What is Privacy?
Answer: The privacy rule in a database states that only authorized users can access a database according to its privacy constraints.
22. What is Backup?
Answer: Backup is a process to copy the data to the other storage device. DBMS has an inbuilt backup facility. it takes the backup periodically.
23. What is Recovery?
Answer: Recovery means restoring the database from backup, after a crash or system failure to its previous condition.
24. What do you mean by Data consistency?
Answer: Data consistency means there should be multiple mismatching copies of the same data i.e. must not present the different information about the same entity.
25. What are the key features of a database?
Answer: There are some key features of a database. These are:-
(a) A database can have one or many tables.
(b) Each table in a database contains information about one type of item.
(c) Every record must be unique in a table.
(d) Every database table should have one or more fields as the Primary key, for differentiating records.
26. How is data organized in an RDBMS?
Answer: In RDBMS, data is organized into tables.
A relational database is a type of database. It uses a structure that allows us to identify and access data in relation to another piece of data in the database.
27. What do you mean by the table?
Answer: A Table refers to a storage container storing data pertaining to a single object, subject, or purpose. A table in a relational database is called a relation.
28. What are the components of a table?
Answer: Components of the table are:-
(a) Fields / Data Item / Attribute / Columns :- Represents one type of information. A data item is the smallest unit of named data.
(b) Records / Tuple / Rows:- A record is a named collection of data items that represents a complete unit of information.
(c) Relation / Table:- A table is a named collection of all occurrences of a given type of logical record. Also known as Relation.
29. Write the name of the components given in the figure?
Answer: 1. Column / Field / Data item / Attribute ,
2. Row / Record / Tuple,
3. Table / Relation
30. What is RDBMS?
Answer: RDBMS stands for Relational Database Management System. It is a system that is based
on a relational model. The purpose of the relational model is to provide a declarative method for specifying data and queries. A relational model enables users to store data in several tables. It has the capability to retrieve data from related tables.
31. What is Primary Key?
Answer: Primary Key is a field that uniquely identifies the records in a table.
32. What is Composite Key or Composite Primary Key?
Answer: The primary key that consists of a combination of two or more fields or attributes is known as the Composite key or composite primary key.
33. What is Candidate Key?
Answer: All fields or field combinations that are eligible to be a primary key, called the Candidate key.
34. What is Alternate Key?
Answer: The keys that have the unique values for each record but are not selected as the primary key i.e candidate keys not selected as primary keys, are called Alternate keys.
35. What is Foreign Key?
Answer: A non-primary key filed / attribute in a table, which is a primary key in other tables, is called Foreign Key. It is used to implement referential integrity.
36. In the given tables named Teacher & Project, identify the Primary Key, Candidate Key, Alternate Key, Composite Primary key, and Foreign Key.
Answer:
Table Teacher:
Primary Key – TeacherNo,
Candidate Keys – TeacherNo, Name,
Alternate Key – Name,
Table Project:
Composite Primary Key – RollNo and Project,
Foreign Key – TeacherNo
37. What do you mean by Child Table and Parent Table?
Answer: Child Table:- A table that contains a foreign key is called the child table or dependent table.
Parent Table:- A table that contains the foreign key linked primary key is called the parent table or primary table.
Table Project is a child table and table Teacher is a Parent table (given in figure q.no 36)
