The JusDB Database Engineering Blog

Diagnose MySQL 8.4 InnoDB deadlocks from lock evidence, correct ordering and indexing, use SKIP LOCKED only for queues, and retry whole transactions safely.

MySQL 8.0 end-of-life is April 2026. Plan your upgrade to MySQL 8.4 LTS now. Learn migration strategies, new features, and compatibility considerations.

MySQL offers multiple replication topologies — traditional async replication, semi-sync, Group Replication, and InnoDB Cluster. Understanding the trade-offs determines whether your failover takes seconds or minutes.

MySQL transmits data in plaintext by default, exposing passwords and query results to network interception. Here's how to configure SSL/TLS for MySQL — from certificate generation to enforcing encrypted connections.

ProxySQL pools thousands of application connections into a small backend pool, splits reads to replicas automatically, and lets you change routing without touching application code or restarting MySQL.

A complete guide to MySQL JSON functions — JSON column type, JSON_EXTRACT and arrow operators, JSON_SET vs JSON_INSERT vs JSON_REPLACE vs JSON_MERGE_PATCH, functional indexes, and multi-valued indexes for arrays.

Master MySQL index data structures and optimization strategies. Learn B+ tree internals, index selection, covering indexes, and real-world performance case studies.

A production guide to MySQL full-text search — FULLTEXT index creation, MATCH AGAINST in natural language and boolean modes, the 50% rule, InnoDB vs MyISAM FTS, combining with B-tree indexes, and comparison against Elasticsearch.

Essential MySQL diagnostic queries every DBA needs. Quickly identify slow queries, lock contention, replication lag, memory issues, and connection problems.

MySQL replication filters let you replicate only specific databases or tables — but misconfiguration can silently drop transactions. Here's how to use binlog-do-db, replicate-do-db, and replicate-do-table safely.

A comprehensive guide to MySQL replication lag — why it happens, why Seconds_Behind_Master lies, how to measure accurately with pt-heartbeat, and how to fix it with multi-threaded replication and LOGICAL_CLOCK parallelism.

A production guide to online MySQL schema changes — when to use pt-online-schema-change vs gh-ost vs MySQL 8.0 INSTANT DDL, configuration parameters, the cutover mechanism, and a step-by-step safety playbook.