midDatabases
What is the CAP Theorem?
Updated Apr 28, 2026
Short answer
Consistency, Availability, and Partition Tolerance: a distributed system can only provide two of the three.
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?