Relational model overview — evaluate the statement:\n“A relation is a two-dimensional table.” Decide whether this simplification is acceptable in database theory contexts.

Difficulty: Easy

Correct Answer: Correct — a relation can be represented as a two-dimensional table of tuples and attributes

Explanation:


Introduction / Context:
The tabular representation is the most common mental model for relations. While a relation is formally a set of tuples over attributes, it is routinely visualized and manipulated as a two-dimensional table.



Given Data / Assumptions:

  • Rows correspond to tuples (records).
  • Columns correspond to attributes (fields).
  • Order of rows and columns in formal theory is not significant; duplicates are not allowed in a strict relation.


Concept / Approach:
Calling a relation a “two-dimensional table” is an acceptable pedagogical simplification used in textbooks and practice. The key is to remember the underlying set semantics: no duplicate tuples, attribute names define columns, and order does not matter. Within those caveats, the statement is considered correct for introductory and applied contexts.



Step-by-Step Solution:

Map formal concepts to table semantics.Recognize the 2D grid representation as conventional.Account for set-based nuances: ordering and duplicates are theoretical differences from many SQL systems.Conclude the statement is acceptable as a simplification.


Verification / Alternative check:
SQL DDL/DML operate on tables whose abstraction mirrors relations; relational algebra operations (selection, projection, join) align with tabular processing.



Why Other Options Are Wrong:

  • Relations are not graphs or multidimensional arrays by definition.
  • The description is not limited to a specific DBMS; it is a model-level view.


Common Pitfalls:
Forgetting that a relation is a set (no duplicates) and that order is not defined; assuming SQL table behaviors (like duplicates) always match theory.



Final Answer:
Correct — a relation can be represented as a two-dimensional table of tuples and attributes

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