Locking and performance

Row-level locking improves concurrency in a multi-user system. However, a large number of row locks can degrade performance.

About the system's selection of lock granularity discussed the way the optimizer makes some compile-time decisions about escalating row locks to table locks for performance reasons. This section discusses ways in which the Derby system and the user can make similar lock escalations.

Related concepts
Performance and optimization
Non-cost-based optimizations
Overriding the default optimizer behavior