Enscribe is the native hierarchical database in HP NonStop (Tandem) servers. It supports the five file structures: unstructured, key-sequenced, entry-sequenced, relative and queue. Enscribe supports partitioned files which spans across multiple physical disks. It supports locking at file and record levels. The Guardian APIs or the utility FUP (File Utility Program) can be used to work with Enscribe files. Many of the applications developed in HP NonStop servers (often critical ones) runs on Enscribe databases.