Definition - What does Tuning mean?
Database tuning is the process performed by database administrators of optimizing performance of a database. In the enterprise, this usually means the maintenance of a large database management system (DBMS) such as Oracle or MySQL. This includes optimizing the performance of the database itself as well as the underlying hardware.
Techopedia explains Tuning
Since many businesses rely on complex database management systems, it is important to keep them running efficiently. Tuning means examining all parts of a database system, including all hardware and software, to minimize bottlenecks and keep query response times as short as possible.
Tuning encompasses the selection of hardware for servers, setting up RAID systems, deploying clusters and configuring operating systems as well as the database itself for optimum performance. Database tuning is typically done by database administrators or system administrators. Because it is such a complex process, research is being done into automating database tuning with machine learning.