Concurrent Database Requests Explained: Pessimistic vs Optimistic Locking скачать в хорошем качестве

Concurrent Database Requests Explained: Pessimistic vs Optimistic Locking

Concurrency bugs are some of the most expensive failures in production systems — not because they’re rare, but because they’re silent. In this video, we break down concurrent database requests from a Principal Engineer’s perspective. You’ll learn why race conditions happen, why application-level locks don’t work at scale, and how databases actually protect consistency under concurrent access. We’ll walk through: What concurrency really means at the database level The classic lost update problem Why async code ≠ database safety Pessimistic concurrency control (locking, SELECT … FOR UPDATE) Optimistic concurrency control (versioning, retries, fail-fast) Real trade-offs between correctness, latency, and scalability How Principal engineers design systems that contain conflicts instead of eliminating them This video is not about writing more locks — it’s about thinking in system invariants, failure modes, and business trade-offs. 👨‍💻 Best for: Senior Engineers • Staff Engineers • Principal Engineers • System Design Interviews • Backend & Distributed Systems