midDatabases
Difference between Optimistic and Pessimistic Locking.
Updated Apr 28, 2026
Short answer
Pessimistic locks the data for the duration; Optimistic checks for changes before commit.
Deep explanation
Exploring concurrency control. How MVCC (Multi-Version Concurrency Control) works to allow readers and writers to operate without blocking each other.
Real-world example
Banking systems using SERIALIZABLE isolation to prevent double-spending.
Common mistakes
- Over-indexing tables which slows down INSERT/UPDATE operations.
Follow-up questions
- What is Dirty Read?