Database Basic Knowledge Quiz! Trivia

In ERD (Entity Relationship Diagram), rectangles are used to represent entity types. Entity types are the main objects or concepts in a database, such as customers, products, or employees. The rectangles in an ERD visually depict these entity types and their relationships with other entities. They help to define the structure and organization of the database by showing the different entities and how they are related to each other.

In Hierarchical DBMS, a parent can have multiple children. This is because the hierarchical model allows for a one-to-many relationship between a parent and its children. Each parent can have multiple children, but each child can have only one parent. This structure is similar to a tree, where each node (parent) can have multiple branches (children). Therefore, the statement that a parent can have only one child in a Hierarchical DBMS is incorrect.

Entities can be associated with one another through relationships. Relationships define the connections or associations between different entities in a database. They represent how entities are related or connected to each other. Relationships can be one-to-one, one-to-many, or many-to-many, and they help in organizing and structuring the data in a database. By establishing relationships between entities, it becomes possible to retrieve and manipulate data in a meaningful and efficient manner.

Data and information are not indistinguishable terms. Data refers to raw facts, figures, or symbols that have no meaning on their own. Information, on the other hand, is processed and organized data that has meaning and context. In other words, data is the raw material, while information is the result of analyzing and interpreting that data. Therefore, the correct answer is false.

An ER Diagram is not an example of a physical schema. ER Diagrams are graphical representations of entities and their relationships in a database, used to design and communicate the logical structure of a database. A physical schema, on the other hand, defines how the data is actually stored and organized on a physical storage medium such as a hard drive or a server.

An ER diagram is a visual representation of the entities (objects or concepts) and the relationships between them in a database. It helps to define the structure and organization of the data. Resources, on the other hand, refer to the external elements that are used by the entities, such as files or services. Therefore, the statement that an ER diagram consists of entities and resources is true, as it accurately describes the components included in an ER diagram.

A multi-valued attribute is an attribute that can have multiple values for a single entity. It is not common to many entities, but rather specific to a single entity. Therefore, the statement that a multi-valued attribute is common to many entities is false.

A derived attribute is a attribute that can be calculated or derived from other attributes in the database. It does not need to be physically stored because its value can be determined by performing calculations or operations on other stored attributes. Therefore, a derived attribute does not require its own physical storage space within the database.

A ternary relationship exists when three entities are associated. This means that there is a relationship between three different entities, rather than just two. In a ternary relationship, each entity is connected to the other two entities in some way. This type of relationship is often represented in a database or data model, where the relationships between entities need to be defined and organized.

The external schema in the three-schema model represents how the user views the database. It defines the user's perspective and includes specific views or subsets of data that are relevant to their needs. This schema allows users to interact with the database without needing to understand its internal structure or physical implementation. It provides a simplified and customized view of the database for different user groups or applications.