The JusDB Database Engineering Blog

Deploy Aurora Global Database for sub-second cross-region replication. Understand storage-level replication, planned failover vs unplanned, and write forwarding for read regions.

Five counterintuitive database performance truths every engineer gets wrong — over-indexing costs, N+1 queries, connection pool sizing, replica reads, and EXPLAIN limitations.

TiDB performs schema changes online without blocking reads or writes — using a distributed DDL queue across TiDB nodes. Here's how it works and how to monitor DDL jobs in production.

RDS MySQL audit logs stored in CloudWatch cost significantly more than S3 — and most teams don't need real-time log access. Here's how to export audit logs to S3 and cut your AWS bill.

MongoDB's Slot-Based Execution (SBE) engine introduced a plan cache memory leak affecting certain MongoDB versions — here's how to detect, mitigate, and fix it.

A critical bug in MongoDB 8.0 (SERVER-97368) affects TTL index behavior — causing documents to persist beyond expiration or delete prematurely. Here's how to detect and mitigate it.

Understand when MySQL JSON columns help and hurt performance. Learn functional indexes, JSON_TABLE, and when to migrate JSON to normalized columns.

AWS DMS can migrate terabytes of data with zero downtime — but default settings leave significant performance on the table. Here's how to tune DMS for production-grade migrations.

Teams take down production for hours with migrations that could be zero-downtime operations. Learn to use gh-ost and CREATE INDEX CONCURRENTLY, implement rollback plans, and apply the expand-contract pattern for breaking changes.

MySQL's foreign key implementation has evolved significantly from 5.7 through 8.4 — with changes to metadata locking, instant DDL interactions, and Group Replication behavior that every DBA needs to understand.

In 2026, more database versions are hitting end-of-life than any year in recent history.

Master InnoDB buffer pool internals: page management, chunk allocation, LRU algorithm, and tuning strategies for maximum cache efficiency.