1. HBase：
该模型用于提供对大量结构化数据的随机访问。它建立在 hadoop 文件系统的顶部，本质上是面向列的。它用于将数据存储在 HDFS 中。它是提供数据复制的开源数据库。 HBase 的三个重要组件是 HMaster、Region 服务器、Zookeeper。
2. PostgreSQL :
PostgreSQL 是一个强大的开源对象关系数据库系统。由于其高稳定性，它以低维护工作提供良好的性能。 PostgreSQL 是第一个实现多版本并发控制 (MVCC) 功能的 DBMS。
PostgreSQL 和 HBase 的区别：
| S.No. | HBase | PostgreSQL |
|---|---|---|
| 1. | HBase is written in JAVA. | PostgreSQL is written in C languages. |
| 2. | It does not supports SQL query language. | It supports SQL query language. |
| 3. | It does not support XML Format. | It supports XML Format. |
| 4. | It has no Secondary database models. | It has Document store as Secondary database models. |
| 5. | It supports in-memory capabilities. | It does not supports in-memory capabilities. |
| 6. | HBase uses a selectable replication factor. | It doesn’t use selectable replication factor. |
| 7. | HBase is less complex than PostgreSQL. | It is more complex than HBase. |
| 8. | HBase has triggers. | PostgreSQL doesn’t have triggers. |
| 9. | HBase is based on Bigtable. | PostgreSQL is based on RDBMS. |
| 10. | HBase provide more consistency. | It provide less consistency. |