1.德比：
Derby 是一个开源的关系数据库管理系统。它由 Apache 软件基金会于 1997 年开发。它完全用Java编程语言编写和实现。 Derby 的主要数据库模型是关系 DBMS。所有带有Java VM 的操作系统都是服务器操作系统。它根据 SQL 标准为用户提供细粒度的访问权限，并具有可紧密嵌入到任何基于Java的解决方案中的小型基于标准的数据库引擎。
2. 黑斑羚：
Impala 是一个运行在 Hadoop 上的查询引擎。它是一个开源软件和大规模并行处理的 SQL 查询引擎。它支持内存数据处理。它率先使用 Parquet 文件格式，这是一种列式存储布局，针对数据仓库场景中典型的大规模查询进行了优化。它提供高性能、低延迟的 SQL 查询，还提供对以 Hadoop 文件格式存储的数据的交互式查询处理。
Derby 和 Impala 的区别：
| Derby | Impala |
|---|---|
| It is developed by Apache Software Foundation in 1997. | It is developed by Cloudera in 2013. |
| It is written and implemented in Java. | It is written and implemented in SQL. |
| It provides Immediate Consistency concept. | It provides Eventual Consistency concept. |
| It support In-memory capabilities. | It do not support In-memory capabilities. |
| It support ACID Transaction concepts. | No transaction concepts. |
| It does not support map reduce method. | It support map reduce method. |
| It does not support Partitioning methods. | It support Sharding Partitioning methods. |
| It support fine grained access rights according to SQL-standard. | It support access rights for users, groups and roles. |
| Proprietary protocol using JSON are used as APIs and other access methods. | JDBC and ODBC are used as APIs and access methods. |