Mysql

Hierarchical Tree Structures in MySQL

A relational database stores data in flat tables rows and columns. But real-world data is often hierarchical: a company has departments, departments have teams, teams have employees. File systems have folders inside folders. Comment threads have replies inside replies. The challenge is that SQL tables have no built-in concept of "parent" or "child". We have to model that relationship ourselves. This article covers two ways to do it, using a company org chart as the running example.

Mastering Firewall Rules with firewalld (Linux Security Guide)

Managing firewall rules is not just a server task — it is your first line of defense. A properly configured firewall protects your server from unnecessary exposure.

MySQL DBA Mastery: Administration & Performance Guide

A complete and practical MySQL administration and performance guide covering user management, SSL configuration, database backup & restore, grants, monitoring, query optimization, troubleshooting, and production-ready DBA operations.