The buffer pool manager is a central component of ADABAS, a high performance scaleable database system for OLTP processing. High efficiency and scalability of the buffer pool manager is mandatory for ADABAS on all supported platforms. In order to allow a maximum of parallelism without facing the danger of deadlocks, a multi-version locking method is used. Partitioning of central data structures is another key to performance. Variable page sizes allow for flexible tuning, but make the buffer pool logic more sophisticated, in particular concerning parallelism.