The role of a database administrator (DBA) in managing data systems involves overseeing, maintaining, and optimizing databases to ensure data integrity, security, and availability. DBAs design and implement database structures, manage backups, and restore data in case of failures. They also monitor performance, conduct capacity planning, and enforce data access policies. Additionally, they work closely with developers to optimize queries and indexes, ensuring efficient data retrieval. Overall, DBAs play a crucial role in enabling organizations to utilize data effectively for decision-making.