DBMS Trivia Quiz Questions

1. Which one of the following attribute can be taken as a primary key?

Name

Street

ID

Department

The attribute "ID" can be taken as a primary key because it is likely to be a unique identifier for each record in the database. Primary keys are used to uniquely identify each record in a table, and it is important for them to have unique values to ensure data integrity and avoid duplication. The attributes "Name", "Street", and "Department" are not suitable as primary keys because they are not guaranteed to be unique for each record.

Explanation

The attribute "ID" can be taken as a primary key because it is likely to be a unique identifier for each record in the database. Primary keys are used to uniquely identify each record in a table, and it is important for them to have unique values to ensure data integrity and avoid duplication. The attributes "Name", "Street", and "Department" are not suitable as primary keys because they are not guaranteed to be unique for each record.

2. Database management systems are intended to

Eliminate data redundancy

Establish relationships among records in different files

Manage file access

All of the above

A database management system (DBMS) is designed to eliminate data redundancy by storing data in a centralized location and ensuring that each piece of data is only stored once. It also establishes relationships among records in different files, allowing for efficient data retrieval and analysis. Additionally, a DBMS manages file access by controlling who can access and manipulate the data stored in the database. Therefore, all of the given options are correct as they describe the main purposes and functions of a DBMS.

Explanation

A database management system (DBMS) is designed to eliminate data redundancy by storing data in a centralized location and ensuring that each piece of data is only stored once. It also establishes relationships among records in different files, allowing for efficient data retrieval and analysis. Additionally, a DBMS manages file access by controlling who can access and manipulate the data stored in the database. Therefore, all of the given options are correct as they describe the main purposes and functions of a DBMS.

3. In SQL, which command is used to select only one copy of each set of duplicable rows

SELECT DISTINCT

SELECT UNIQUE

SELECT DIFFERENT

None of the above

The SELECT DISTINCT command is used in SQL to select only one copy of each set of duplicable rows. This means that it will eliminate any duplicate rows in the result set, ensuring that each row is unique. The other options, SELECT UNIQUE and SELECT DIFFERENT, are not valid SQL commands and therefore are not the correct answer.

Explanation

The SELECT DISTINCT command is used in SQL to select only one copy of each set of duplicable rows. This means that it will eliminate any duplicate rows in the result set, ensuring that each row is unique. The other options, SELECT UNIQUE and SELECT DIFFERENT, are not valid SQL commands and therefore are not the correct answer.

4. Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record?

Super Key

Candidate Key

Sub Key

Foreign Key

A super key is a set of one or more attributes that can uniquely identify a record in a database. It may contain extra attributes that are not necessary for uniqueness. In other words, a super key is a superset of a candidate key. Therefore, a super key is the correct answer as it satisfies the condition of uniquely identifying a record.

Explanation

A super key is a set of one or more attributes that can uniquely identify a record in a database. It may contain extra attributes that are not necessary for uniqueness. In other words, a super key is a superset of a candidate key. Therefore, a super key is the correct answer as it satisfies the condition of uniquely identifying a record.

5. In SQL, which of the following is not a data definition language commands?

RENAME

REVOKE

GRANT

UPDATE

UPDATE is not a data definition language (DDL) command in SQL. DDL commands are used to define or modify the structure of the database, such as creating or altering tables, indexes, and constraints. UPDATE is a data manipulation language (DML) command used to modify the data within the tables, not the structure of the database itself.

Explanation

UPDATE is not a data definition language (DDL) command in SQL. DDL commands are used to define or modify the structure of the database, such as creating or altering tables, indexes, and constraints. UPDATE is a data manipulation language (DML) command used to modify the data within the tables, not the structure of the database itself.