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Q91 / 100
What is the difference between PostgreSQL's MVCC and MySQL InnoDB's MVCC?
Correct! Well done.
Incorrect.
The correct answer is B) PostgreSQL keeps old versions in the heap (requires VACUUM); InnoDB stores old versions in a separate undo log, with automatic cleanup via purge threads
B
Correct Answer
PostgreSQL keeps old versions in the heap (requires VACUUM); InnoDB stores old versions in a separate undo log, with automatic cleanup via purge threads
Explanation
PostgreSQL: dead tuples stay in heap pages until VACUUM reclaims them (table bloat risk). InnoDB: undo log stores versions, purged by background threads. Different approaches to old version management.
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