MySQL design feature: In MySQL, surrogate key columns typically use the AUTO_INCREMENT property to generate sequential identifiers. Is that statement accurate?

Difficulty: Easy

Correct Answer: Correct

Explanation:


Introduction / Context:
Surrogate keys are system-generated identifiers that uniquely identify rows. In MySQL, AUTO_INCREMENT is a common mechanism for producing such numeric keys without client-side generation.



Given Data / Assumptions:

  • A column is defined as an integer type with AUTO_INCREMENT.
  • Each insert without an explicit value produces the next sequence number.
  • Engines such as InnoDB fully support AUTO_INCREMENT semantics.



Concept / Approach:
Using AUTO_INCREMENT simplifies key management and avoids collisions. It is distinct from natural keys and from GUID/UUID strategies. AUTO_INCREMENT may have configuration nuances (increment step, starting value, behavior under replication).



Step-by-Step Solution:
Define a table with id INT PRIMARY KEY AUTO_INCREMENT.Insert rows without specifying id.Retrieve generated values via LAST_INSERT_ID().Adjust starting values with ALTER TABLE ... AUTO_INCREMENT = n.Consider uniqueness and gaps under rollbacks or deletes.



Verification / Alternative check:
Run sample DDL/DML and observe increasing identifiers.



Why Other Options Are Wrong:
Support is not limited to legacy engines or versions; modern MySQL/InnoDB support this feature robustly.



Common Pitfalls:
Assuming sequential without gaps; relying on order semantics of generated values.



Final Answer:
Correct

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