ObjectDB is a cross platform software and can be used on various operating systems with Java SE 5 or higher. It can be integrated into
Java EE and
Spring web applications and deployed on servlet containers (
Tomcat,
Jetty) as well as on Java EE application servers (
GlassFish,
JBoss). It was tested on various
JVMs, including
HotSpot,
JRockit and
IBM J9. The maximum database size is 128 TB (131,072 GB). The number of objects in a database is unlimited (except by the database size). All the persistable types of JPA and JDO are supported by ObjectDB, including user defined entity classes, user defined embeddable classes, standard Java collections, basic data types (primitive values, wrapper values, String, Date, Time, Timestamp) and any other serializable classes. Every object in the database has a unique ID. ObjectDB supports both traditional object database IDs, as well as RDBMS like primary keys, including composite primary keys and auto value generation and assignment, as part of its support of
JPA, which is mainly an API for RDBMS. Two query languages are supported. The JDO Query Language (
JDOQL), which is based on Java syntax, and the JPA Query Language (
JPQL), which is based on
SQL syntax. JPA 2 criteria queries are also supported. ObjectDB automatic
schema evolution handles most changes to classes transparently, including adding and removing of persistent fields, changing types of persistent fields, and modifying class hierarchy. Renaming persistable classes and persistent fields is also supported. ==Tools and utilities==