PostgreSQL is an open-source Relational Database Management System (RDBMS) that supports complex data types, ACID-compliant transactions. The RDBMS is widely used in web applications, data warehousing, and geospatial data management. PostgreSQL supports Structured Query Language (SQL) for storing and retrieving data in tables. This article explains how to install PostgreSQL on Rocky Linux 9 and how to enable authentication for database users. Before you begin: * Deploy a [Rocky Linux 9](https://......