In IBM DB2, which of the following data types CANNOT be used in a sensible way to store the date on which an employee was hired, assuming you want the data type itself to represent the date correctly rather than just storing characters?

Introduction / Context:
When designing database tables, choosing appropriate data types is crucial for correctness, storage efficiency, and query performance. IBM DB2 supports several data types for storing textual, temporal, and numeric data. This question focuses on which data type cannot meaningfully represent the date an employee was hired if you want the type itself to capture date information, not just store arbitrary characters.

Given Data / Assumptions:

• You need to store the hire date of each employee in a DB2 table.
• The options include CLOB, TIME, VARCHAR, TIMESTAMP, and DATE.
• The goal is to choose a type that inherently represents the calendar date, not merely a string of characters.
• We assume normal relational database design practices, not workarounds.

Concept / Approach:
In DB2, DATE and TIMESTAMP are designed to store date related information. DATE typically stores year, month, and day. TIMESTAMP stores date and time components. VARCHAR and CLOB are character types; while you technically could store dates as strings in them, the database would not inherently recognize them as date values. However, the question focuses on which type cannot be used to contain the date in a meaningful temporal sense. The TIME data type stores only the time of day (hours, minutes, seconds) without any date component, so it cannot correctly represent a specific calendar date such as an employee's hire date.

Step-by-Step Solution:
1. Consider DATE: it is specifically built to store year month day values, so it clearly can store a hire date. 2. Consider TIMESTAMP: it stores both date and time, so it can also correctly represent the moment an employee was hired. 3. Consider VARCHAR and CLOB: although they are not ideal, they can technically contain textual representations of dates, such as '2026-01-15', but the database does not enforce date semantics. 4. Consider TIME: it only stores hours, minutes, and seconds without any associated date, so it cannot indicate which day the hiring occurred. 5. Conclude that TIME is the one type that cannot meaningfully contain the date of hire.

Verification / Alternative check:
If you attempt to store a full date in a TIME column, DB2 will either reject it or store only the time portion, discarding the date. Queries that need to compare or sort by hire date would not work correctly because the day, month, and year are not stored. By contrast, DATE and TIMESTAMP columns support date functions, comparisons, and indexing based on actual calendar values, confirming that they are appropriate for representing hire dates.

Why Other Options Are Wrong:
Option a: CLOB can store large amounts of text, including date strings; although not ideal, it can technically contain the hire date as text. Option c: VARCHAR can store formatted date strings such as '2026-01-15' and can contain the hire date, even though it lacks built in date semantics. Option d: TIMESTAMP fully supports date and time information and is often used for audit columns like created_at or hired_at. Option e: DATE is the most natural and intended datatype for storing a hire date in DB2.

Common Pitfalls:
A common mistake is to misuse character types for dates because it seems easy. This makes it harder to validate format and perform date calculations or comparisons. Another pitfall is confusing TIME and TIMESTAMP; developers sometimes assume TIME includes a date, but it does not. Whenever you need to represent a specific day, always choose DATE or TIMESTAMP rather than TIME or generic character types.

Final Answer:
The DB2 data type that cannot meaningfully represent an employee's hire date is TIME, because it stores only time of day without any calendar date information.