Relational Database Management System Quiz

Relational database systems primarily employ SQL (Structured Query Language). SQL is a standard programming language used for managing and manipulating relational databases. It allows users to create, modify, and retrieve data from databases, as well as perform various operations such as querying, updating, and deleting data. While C# and Java are popular programming languages, they are not specifically designed for relational database management like SQL. Therefore, the correct answer is SQL.

The purpose of an indexed field in a database is to speed up queries. By creating an index on a specific field, the database system can organize and sort the data in a way that allows for faster retrieval of specific information. This is especially useful when dealing with large amounts of data, as it helps to optimize the performance of queries and improve the overall efficiency of the database system.

Cardinality refers to the number of instances of one entity that can be associated with another entity in a relationship. It describes the frequency or occurrence of the relationship between entities. For example, in a one-to-one cardinality, each instance of one entity is associated with only one instance of another entity. In a one-to-many cardinality, each instance of one entity can be associated with multiple instances of another entity. Cardinality helps in understanding the nature and constraints of the relationship between entities in a database.

The requirement that each entity must have a unique primary key where the value of that primary key is not null is known as the Entity Integrity Rule. This rule ensures that each entity in a database has a unique identifier that is not null, which helps maintain data integrity and allows for efficient data retrieval and manipulation.

The referential integrity rule states that for each foreign key in a relational database, there must be a corresponding primary key. This means that the value in the foreign key column of a table must match a value in the primary key column of another table. This ensures that there is a valid relationship between the two tables and prevents orphaned records. Without a corresponding primary key, the foreign key would be meaningless and the relationship between the tables would be compromised.

The given statement implies that if we have the Pupil_no, we can determine the corresponding Pupil_name. This indicates that the Pupil_name is functionally dependent on the Pupil_ID, as the Pupil_ID (or Pupil_no) determines the value of Pupil_name. Therefore, the correct answer is that Pupil_name is functionally dependent on Pupil_ID.

This is a popular wrong answer. Relationships are not just formed by links between foreign keys.

In relational database design, it is true that no row should be duplicated. This is because each row in a table represents a unique entity or instance, and duplicating rows would result in redundancy and data inconsistency. To ensure data integrity and efficiency, it is important to maintain a single instance of each row in the table. This can be achieved by using primary keys to uniquely identify each row and enforcing constraints to prevent duplicate entries.

In the given entity, CAR_RENTAL, the attribute Driver_Name would be included in a repeating group. A repeating group occurs when multiple values of an attribute are allowed for a single occurrence of an entity. In this case, it is possible for a car to be rented by multiple drivers, hence the attribute Driver_Name would have multiple values, making it a repeating group.

If there are multiple occurrences of attributes for a single value of a primary key, this is known as a repeating group. In a database, a primary key is a unique identifier for each record in a table. However, in some cases, there may be multiple instances of attributes associated with a single primary key value. This is referred to as a repeating group, as it involves repeating the same set of attributes for a specific primary key value.