Databases Articles | Backend Study Lab

System Design Jul 1, 2026 6 min read

Database Connection Pooling Explained

Learn database connection pooling for backend systems, including pool size, timeouts, leaks, max connections, queues, monitoring, and common mistakes.

System Design Jul 1, 2026 6 min read

Database Migration Rollback Explained

Learn database migration rollback strategies, including backward-compatible changes, expand-contract migrations, backups, deploy order, and recovery plans.

System Design Jul 1, 2026 5 min read

N+1 Query Problem Explained

Learn the N+1 query problem in backend apps, including ORM loading, SQL examples, eager loading, batching, joins, query counts, and fixes.

System Design Jun 29, 2026 5 min read

Database Sharding Explained

Learn what database sharding is, when backend systems need it, how shard keys work, and what tradeoffs sharding creates.

System Design Jun 29, 2026 4 min read

Database Transactions Explained

Learn what database transactions are, why ACID matters, how commits and rollbacks work, and what backend developers should know.

System Design Jun 28, 2026 4 min read

Database Indexes Explained

Learn how database indexes work, why they speed up reads, when they slow down writes, and how backend developers should choose indexes.

System Design Jun 28, 2026 4 min read

Optimistic Locking Explained

Learn how optimistic locking prevents lost updates in backend systems using version columns, compare-and-swap updates, and 409 conflicts.