Is autocommit enabled by default in MySQL?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of SQL & Databases conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
Yes, in MySQL (using the standard InnoDB storage engine), autocommit is enabled by default (autocommit = 1):
### What Autocommit Means:
- Every individual SQL statement (
INSERT,UPDATE,DELETE) is automatically wrapped in its own single-statement transaction and committed immediately. - To execute multi-statement atomic transactions, you must explicitly start a transaction block:
START TRANSACTION;
-- Multiple queries here...
COMMIT;
Or disable autocommit for the session: SET autocommit = 0;.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.