Apache Derby features
*ANSI/ISO standard SQL*
Transactions, isolation levels, row-level locking
Subselects, views, relational constraints
Triggers, stored procedures, user-defined functions
*Ease of use*
Small footprint: 4 MB JAR file + JVM (one JVM for database, one JVM for network server)
No or low administration effort required
SQL interfaces for common tasks like backup
*Security*
Authentication (LDAP, custom, built-in)
Database encryption
*Performance*
200 transactions / second on an untuned system
20-30 concurrent users with connection pooling