State true/false: “A hierarchical database uses many-to-many relationships.
The Correct Answer and Explanation is:
Statement: “A hierarchical database uses many-to-many relationships.”
Answer: False
Explanation
A hierarchical database organizes data in a tree-like structure, where each record (called a node) has a single parent and potentially many children. This structure is based on one-to-many relationships, not many-to-many relationships.
In a hierarchical database:
- One parent node can have multiple child nodes, representing a one-to-many relationship.
- Each child node has only one parent, meaning the structure does not allow a record to be associated with multiple parents directly.
This model was widely used in early database systems such as IBM’s Information Management System (IMS). The rigid hierarchy simplifies certain queries and makes data access efficient when working with predictable, structured relationships. However, it lacks flexibility for more complex data interactions.
In contrast, a many-to-many relationship occurs when multiple records in one table are associated with multiple records in another table. This kind of relationship is not directly supported in a hierarchical database. To simulate many-to-many relationships, developers would need to introduce redundant data or bridge tables, which can lead to complexity and inefficiency.
For example, in a school database:
- A teacher teaching many students, and each student learning from multiple teachers, forms a many-to-many relationship.
- This scenario is difficult to represent naturally in a hierarchical model because a student cannot easily appear under multiple teacher nodes.
Relational databases (RDBMS) are better suited for many-to-many relationships because they support foreign keys and join operations, allowing for more flexible data modeling.
In summary, hierarchical databases are based on one-to-many relationships, not many-to-many. This structural limitation makes them less ideal for complex data interconnections, which is why modern applications often favor relational or NoSQL databases.
