A DBMS's configuration knobs control aspects of its runtime operations. The three categories of knobs are (1) resources, (2) policies, and (3) locations. Knobs in the first category specify how much of a resource the system uses for a task. These can be either for fixed components (e.g., the number of garbage collection threads) or for dynamic activities (e.g., the amount of memory to use per query). Policy configuration knobs control how the DBMS behaves for specific tasks. For example, a knob can control whether the DBMS flushes the write-ahead log to disk when a transaction commits. Lastly, the location knobs specify where the DBMS finds resources that it needs (e.g., file paths) and how it interacts with the outside world (e.g., network port number).