In relational terminology, an attribute is best defined as which of the following within a table (relation)?
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Acolumn of a table.
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Btwo dimensional table.
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Crow of a table.
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Dkey of a table.
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Eindex over multiple rows.
Answer
Correct Answer: column of a table.
Explanation
Introduction / Context:Relational vocabulary maps everyday database objects to formal terms. Correctly matching “attribute” clarifies subsequent topics like functional dependencies and normalization.
Given Data / Assumptions:
- “Attribute” is a formal term from relational theory.
- Tables (relations) are composed of rows (tuples) and columns (attributes).
- Keys and indexes are separate constructs.
Concept / Approach:An attribute is the column definition—name and domain (data type)—for values stored per row. Attributes collectively define the schema of the relation.
Step-by-Step Solution:
Map terms: attribute ↔ column; tuple ↔ row; relation ↔ table.Therefore, “attribute” means “column of a table.”Verification / Alternative check:Any relational database textbook or SQL standard-based glossary reflects this mapping.
Why Other Options Are Wrong:Two-dimensional table / row / key / index: Those are different concepts; an attribute is not a whole table, a row, a key, or an index.
Common Pitfalls:Confusing attribute with field in certain contexts; “field” is an implementation term, while “attribute” is the relational theoretical term.
Final Answer:column of a table.