Derby supports SERIALIZABLE
(RR), REPEATABLE (RS), READ COMMITTED (CS), and READ UNCOMMITTED (UR) isolation
levels.
- CS
- CS (the default isolation level) provides the best balance between concurrency
and consistency in multiple-client environments.
- RS
- RS provides less consistency than RR but allows more concurrency.
- RR
- RR provides greatest consistency.
- UR
- UR provides maximum concurrency, if uncommitted values are allowed in
the query. It is typically used if approximate results are acceptable.
See "Types and Scope of Locks in Derby Systems"
in the Derby Developer's Guide for
more information.