The yaRDBMS (yet another relational database management system) is a Java based, transactional highly concurrent relational database management system with advanced query optimization, indexing features and crash recovery.
The yaRDBMS uses on write-ahead log (WAL) based transaction management. The development is currently in its early stages. It has basic transaction support, an incomplete JDBC driver and basic SQL support (only two-table joins are supported for the time being). What is totally lacking currently is security and crash recovery.
The yaRDBMS uses B+ trees for indexing (currently only for the primary keys.