OrientDB 1.7 rc2 发布，此版本更新内容如下：
核心
supports retro-compatibility for databases created with OrientDB v1.5 or higher
improves performance on ORDER BY against indexes
improves performance on RENAME CLASS.
Graph
it adds support for vertex-centric traversal by using SQL.
SQL
it adds an UPSERT keyword to execute an INSERT or UPDATE based on a condition
UPDATE can now ADD to sub-document fields.
Indexes
it adds support for external engines. For Studio
it adds a new Query Timeline to the History and a new Index Panel.
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。
项目主页：http://www.orientechnologies.com/orientdb/
下载地址：http://www.orientechnologies.com/download/
来自:开源中国社区
