Logical data structures: Which model most directly represents a one-to-many relationship using parent–child hierarchy?
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ARelational
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BTree (hierarchical) model
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CNetwork (CODASYL) model
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DChain
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ENone of the above
Answer
Correct Answer: Tree (hierarchical) model
Explanation
Introduction / Context:Logical data models describe how records relate. The hierarchical (tree) model organizes records in parent–child relationships, naturally expressing one-to-many structures such as categories and subcategories.
Given Data / Assumptions:
- We want a model that directly encodes one parent to many children.
- Relationships are traversed top-down along a single path.
- Alternatives include network (many-to-many) and relational (table-based with keys).
Concept / Approach:The tree (hierarchical) model uses a root and branches. Each child has exactly one parent (in classic form), aligning exactly with one-to-many relationships.
Step-by-Step Solution:
Match requirement (one-to-many) with model traits.Recognize hierarchical structure as parent → multiple children.Choose the tree (hierarchical) model.Verification / Alternative check:Organizational charts and directory trees are real-world examples of hierarchical one-to-many models.
Why Other Options Are Wrong:
- Relational: represents relationships via keys, not inherently hierarchical.
- Network: enables many-to-many via multiple sets, not restricted to one-to-many.
- Chain: not a standard logical model.
Common Pitfalls:Assuming relational implies hierarchy; it can model it, but not intrinsically as a tree does.
Final Answer:Tree (hierarchical) model