The JusDB Database Engineering Blog

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.

Monitor MySQL and PostgreSQL with Prometheus, Grafana, and PMM. Covers mysqld_exporter, postgres_exporter, alert rules, and production dashboard configuration.

Secure your MySQL and PostgreSQL databases — TLS, at-rest encryption, role-based access, and audit logging

Running a single PMM server is a single point of failure for your database monitoring. Here's how to set up PMM in an HA configuration with failover and shared storage.

A deep dive into InnoDB locking — record locks, gap locks, next-key locks, how READ COMMITTED eliminates gap locks, diagnosing deadlocks with SHOW ENGINE INNODB STATUS and performance_schema, and prevention patterns.

MySQL InnoDB supports multiple compression strategies — from ROW_FORMAT=COMPRESSED to transparent page compression using punch holes. Choosing the right approach can cut storage by 40-70% for text-heavy workloads.

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.

Understand MySQL max_connections, thread caching, and connection pool sizing to handle high-concurrency workloads

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.

Deploy PMM to get deep MySQL and PostgreSQL visibility — query analytics, dashboards, and alerting in one tool

MySQL's EXPLAIN command reveals exactly how the query optimizer plans to execute your SQL — which indexes it will use, how many rows it expects to examine, and where it may sort or create temporary tables.