The JusDB Database Engineering Blog

Everything you need to know about MySQL: storage engines, replication topologies, performance tuning, and cloud deployment. From basics to advanced optimization.

MySQL wait_timeout, net_read_timeout, innodb_lock_wait_timeout and max_execution_time — production tuning rules and the HikariCP alignment trick that prevents 'communications link failure' errors.

Configure MySQL binlog retention safely: binlog_expire_logs_seconds, manual purging rules, AWS RDS retention, and the disk-exhaustion failure mode you should monitor for.

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

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.

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

Use MySQL 8.0 generated columns to index computed values, JSON paths, and date parts. Covers virtual vs stored tradeoffs and functional index patterns.

Guide MySQL query execution with optimizer hints. Covers INDEX, NO_INDEX, JOIN_ORDER, MAX_EXECUTION_TIME, and query block naming for subquery hint targeting.

Master MySQL 8.0 window functions for analytical queries. Covers ROW_NUMBER, RANK, LAG/LEAD for period comparison, running totals with SUM OVER, and NTILE quartiles.

The InnoDB redo log default of 100MB is dangerously undersized for production. Learn to measure your write throughput, size innodb_redo_log_capacity correctly, and monitor checkpoint pressure before write stalls occur.

MySQL 8.4's audit log filter system lets you capture exactly the events your compliance framework requires — filtering by user, schema, event class, and severity to reduce audit log volume.

Monitor InnoDB lock contention with performance_schema.data_locks, find blocking transactions, kill them safely, and prevent escalation with short transactions and proper timeouts.