Orient DB 是一个可伸缩的文档数据库，支持 ACID 事务处理。使用 Java 5 实现。
OrientDB是一个开源NoSQL的数据库管理系统，使用Java编写，属于文档形数据库，支持ACID Tx，">Indexes，asynch queries，SQL layer，clustering等等。
OrientDB是兼具文挡数据库的灵活性和图形数据库管理链接能力的可深层次扩展的文档-图形数据库管理系统。可选无模式、全模式或混合模式下。支持许多高级特性，诸如ACID事务、快速索引，原生和SQL查询功能。可以JSON格式导入、导出文档。若不执行昂贵的JOIN操作的话，如同关系数据库可在几毫秒内可检索数以百记的链接文档图。
orientdb 1.0rc2更新日志：
- Fixed multi-threads problems
- Speeded up index searching
- Refactored schema, index and security managers to work in multi-threads
- When use remote as protocol, triggers now work at server-side level
- New SQL BETWEEN operator, useful specially against indexes to execute
ranged queries
- New SQL ALTER CLASS and ALTER PROPERTy to refactor the db schema
- New Console DROP DATABASE command
- New Console INDEXES command that displays the configured indexes
- New DATE type to handle dates only with YYYY/MM/SS
- New SQL distinct() function
- New SQL union(), intersect() and difference() functions to work with
collections
- MVCC (Multi-version Concurrency Control) system is enabled also outside
transactions by default, but can be turned off
- Supported +, -, *, / and % math operations in SQL Query
- Enforced security checks
- GraphDB support multiple edges between two vertexes
- Core is Java5 compatible, the server needs Java6
- 80 issues fixed in total!
下载地址：http://orient.googlecode.com/files/orientdb-1.0rc2.zip