Data quality in relational tables: Each option shows example values seen in a single table. Which option best represents the inconsistent values problem (i.e., the same logical value recorded in varying formats or word orders within the same attribute)?

Introduction / Context:
Data quality issues in databases include inconsistent values, missing values, multivalued attributes, and general-purpose remarks fields. “Inconsistent values” occur when the same logical concept is stored in different formats or sequences, making grouping, searching, and analytics difficult. This question asks you to recognize the pattern that indicates inconsistency within one attribute (column).

Given Data / Assumptions:

• We examine examples from one table and focus on the problem type they illustrate.
• “Inconsistent values” means inconsistent ordering, spelling, abbreviations, or formatting for the same attribute.
• Other problems to contrast: missing values (NULLs), multivalued data (multiple facts in one row or column), and remarks columns (free-form text).

Concept / Approach:

When an attribute should contain a single, consistently formatted value (e.g., a product description split into standardized attributes like color, size, item), but entries appear as “Brown Small Chair,” “Small Chair Brown,” and “Small Brown Chair,” the value is not normalized or standardized. This inconsistency undermines equality matching and GROUP BY operations because semantically identical items look different to the database engine.

Step-by-Step Solution:

Verification / Alternative check:

Try to aggregate counts by product description; inconsistent phrasing produces multiple groups for the same item. A standardized attribute model (separate color, size, item columns) avoids this situation.

Why Other Options Are Wrong:

Three columns with multiple numbers: indicates repeating groups or multivalued attributes, not inconsistency.

Values Brown, NULL, Blue: introduces missing values, not inconsistency.

Long sentence about a car: that is a general-purpose remarks column problem.

Common Pitfalls:

Confusing inconsistent values with synonyms; both harm quality, but inconsistent structure/order/format is the key sign here.

Final Answer:

Three rows have the values Brown Small Chair, Small Chair Brown, and Small Brown Chair in the same column.