The main role of a database administrator (DBA) is to manage and maintain databases effectively, ensuring their availability, performance, and security. DBAs are responsible for tasks such as installation, configuration, and monitoring of database systems. They implement backup and recovery procedures, optimize database performance through tuning, and enforce security measures to protect data integrity. Additionally, DBAs play a crucial role in capacity planning and supporting application development by providing database-related support and ensuring seamless data access for end-users.