Fast Locking
Fast locking works with the segment, legacy, and bucket policy. However, a database cannot use the statistical policy or the range policy with fast locking. With the statistical policy, two transactions that insert the same URI do not know which forest the other one will pick, so the server must use strict locking. With the range policy, there may be two transactions that insert the same URI but with different values for the range index, so the server must use strict locking.