BDB stores arbitrary key/data pairs as byte arrays and supports multiple data items for a single key.
Sleepycat Software was acquired by Oracle Corporation in February 2006, who continued to develop and sell the C Berkeley DB library.
[5] Seltzer and Yigit[6] created a new database, unencumbered by any AT&T patents: an on-disk hash table that outperformed the existing dbm libraries.
The 4.x releases added the ability to replicate log records and create a distributed highly available single-master multi-replica database.
Berkeley DB HA supports online upgrades from one version to the next by maintaining the ability to read and apply the prior release's log records.
Berkeley DB supports database features such as ACID transactions, fine-grained locking, hot backups and replication.
Notable software that still uses Berkeley DB for data storage include: Open-source operating systems and languages such as Perl and Python still support old BerkelyDB interfaces.
[20] Linux operating systems, including those based on Debian,[21] and Fedora[22] ship Berkeley DB 5.3 libraries.
By 2013 there were many alternatives to BDB, and Debian Linux was typical in their decision to completely phase out Berkeley DB, with a preference for the Lightning Memory-Mapped Database (LMDB).