Data Quality Patterns — Identifying the Multivalue, Multicolumn Problem Each option shows example table data. Which option demonstrates the multivalue, multicolumn anti-pattern (storing multiple values across several columns in the same row)?

Introduction:
The multivalue, multicolumn problem arises when multiple values of the same attribute are stored across several columns in a single row (for example, Phone1, Phone2, Phone3). This breaks first normal form (1NF) and complicates querying, indexing, and constraint enforcement. The question asks you to identify this anti-pattern from sample data.

Given Data / Assumptions:

• We are evaluating examples purely for modeling quality.
• 1NF requires atomic values in each column and a fixed number of columns per attribute.
• Phone numbers repeated across columns are a classic symptom.

Concept / Approach:
Compare each example with the 1NF rule. If multiple values of the same attribute appear as separate columns in a single row, the design is violating 1NF and causing maintenance headaches (for example, searching all phone columns, or exceeding a fixed maximum number).

Step-by-Step Solution:
1) Inspect (a): multiple phone numbers in separate columns within one row → multivalue, multicolumn.2) Inspect (b): same tokens in different orders → inconsistent values, not multicolumn.3) Inspect (c): presence of NULL → missing values issue.4) Inspect (d): long free-text → general-purpose remarks problem.5) Therefore, (a) is the correct example.

Verification / Alternative check:
Normalized modeling would create a separate related table (for example, CustomerPhone with CustomerID and PhoneNumber), storing one phone per row.

Why Other Options Are Wrong:

• (b) Inconsistent values: Token order inconsistency, not multiple columns.
• (c) Missing values: NULL indicates absence, not multicolumn.
• (d) Remarks column: Free-text mixture of concepts, not multicolumn.
• (e) JSON array: Multivalue single column (violates 1NF) but not the asked “multicolumn” pattern.

Common Pitfalls:
Confusing multivalue-in-one-column (also a 1NF violation) with multivalue-across-columns. The question specifically targets the multicolumn manifestation.

Final Answer:
Three columns have the values 534-2435, 534-7867, and 546-2356 in the same row.