Multiple Choice Questions
Database Management and Design
Grade: 11
Computer Science: Database Management and Design
1. Topic: Entity-Relationship Diagrams
Question: Which of the following is the correct representation of a one-to-many relationship in an entity-relationship diagram?
a) A solid line with an arrow pointing towards the \”many\” side
b) A solid line with an arrow pointing towards the \”one\” side
c) A dashed line with an arrow pointing towards the \”many\” side
d) A dashed line with an arrow pointing towards the \”one\” side
Answer: c) A dashed line with an arrow pointing towards the \”many\” side
Explanation: In an entity-relationship diagram, a dashed line represents a relationship and an arrow indicates the direction of the relationship. A one-to-many relationship is represented by a dashed line with an arrow pointing towards the \”many\” side. For example, in a database for a school, the relationship between a teacher entity and a student entity would be represented by a dashed line with an arrow pointing towards the student entity, as one teacher can have multiple students.
2. Topic: Relational Algebra
Question: Which of the following operators is used to select specific rows from a relation based on a given condition?
a) Union
b) Intersection
c) Selection
d) Projection
Answer: c) Selection
Explanation: The selection operator in relational algebra is used to select specific rows from a relation based on a given condition. For example, if we have a relation called \”Students\” with attributes like \”Name\”, \”Age\”, and \”Grade\”, we can use the selection operator to select all students who are older than 18 years old by specifying the condition \”Age > 18\”.
3. Topic: Normalization
Question: Which normal form ensures that all non-key attributes are dependent on the entire primary key?
a) First normal form (1NF)
b) Second normal form (2NF)
c) Third normal form (3NF)
d) Fourth normal form (4NF)
Answer: c) Third normal form (3NF)
Explanation: Third normal form (3NF) ensures that all non-key attributes are dependent on the entire primary key and not on any partial key. This means that each non-key attribute should be functionally dependent on the primary key, and not on any other non-key attribute. For example, if we have a relation called \”Orders\” with attributes like \”Order ID\”, \”Product ID\”, \”Customer Name\”, and \”Customer Address\”, 3NF would require that \”Customer Name\” and \”Customer Address\” are dependent on the \”Order ID\” and not on the \”Product ID\”.
4. Topic: Indexing
Question: Which type of indexing technique allows for efficient searching of data based on range queries?
a) B-tree indexing
b) Hash indexing
c) Clustered indexing
d) Dense indexing
Answer: a) B-tree indexing
Explanation: B-tree indexing is a type of indexing technique that allows for efficient searching of data based on range queries. It is commonly used in databases to speed up searches for data within a specific range, such as finding all records with a certain value between a minimum and maximum range. For example, if we have a database of books with attributes like \”Title\”, \”Author\”, and \”Publication Date\”, B-tree indexing can be used to quickly find all books published between a specific range of dates.
5. Topic: SQL
Question: Which SQL statement is used to add a new column to an existing table?
a) ALTER TABLE
b) CREATE TABLE
c) INSERT INTO
d) UPDATE
Answer: a) ALTER TABLE
Explanation: The ALTER TABLE statement in SQL is used to add, modify, or delete columns in an existing table. To add a new column, you would use the ALTER TABLE statement followed by the ADD keyword and specify the column name and data type. For example, to add a \”Phone Number\” column to a table called \”Customers\”, the SQL statement would be \”ALTER TABLE Customers ADD Phone_Number VARCHAR(10)\”.
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