The use of non-volatile semiconductor memory within an extended storage hierarchy promises significant performance improvements for transaction processing. although pagre-addressable semiconductor memories like extended memory, solidstate disks and disk caches are commercially available since several years, no detailed investigation of their use for transaction processing has been performed so far. we present a comprehensive simulation study that compares the performance of these storage types and of different usage forms. the following usage forms are considered: allocation of entire log and database files in non-volatile semiconductor memory, using a socalled write buffer to perform disk writes asynchronously, and caching of database pages at intermediate storage levels (in addition to main memory cahing). simulation results will be presented for the debit-credit workload frequently used in transaction processing benchmarks.