Snapshot isolation, or multi-version concurrency control, can be configured when you are using transactions with your BDB XML application. While transactions are not described in this manual, since snapshot isolation is so commonly used for BDB XML applications, it is worth mentioning here that use of Snapshot Isolation means you must:
Increase the maximum number of concurrent transactions supported by the environment.
Increase the size of your disk cache.
This is because snapshot isolation causes your BDB XML transactional application to use much larger amounts of resources than does a normal transactional application.
For more information, see the Berkeley DB XML Getting Started with Transaction Processing guide.