Cassandra和PostgreSQL之间的区别

1.卡桑德拉(Cassandra)：
Cassandra是一个免费的开放源代码的分布式宽列存储NoSQL数据库管理系统。它由Apache Software Foundation开发，最初于2008年7月发布。Cassandra旨在处理许多商用服务器上的大量数据，提供高可用性而没有单点故障。

2. PostgreSQL：
PostgreSQL是一个功能强大的开源对象关系数据库系统。它具有较高的稳定性，因此可以在较低的维护工作量下提供良好的性能。 PostgreSQL是第一个实现多版本并发控制(MVCC)功能的DBMS。

Cassandra和PostgreSQL之间的区别：

S.NO.	CASSANDRA	POSTGRESQL
1.	Developed by Apache Software foundation and released on July 2008.	Developed By  PostgreSQL Global Development Group on 1989.
2.	It is wide-column store based on ideas of BigTable and DynamoDB.	It is widely used open source RDBMS.
3.	Cassandra is written in Java languages.	PostgreSQL is written in C languages.
4.	The primary database model for Cassandra is Wide column store.	The primary database model for PostgreSQL is Relational DBMS.
5.	It has no Secondary database models.	It has Document store as Secondary database models.
6.	Server operating systems for Cassandra are BSD, Linux, OS X and Windows.	Server operating systems for PostgreSQL are FreeBSD, HP-UX, Linux, NetBSD, OpenBSD, OS X, Solaris, Unix and Windows.
7.	It does not support XML format.	It supports XML format.
8.	It supports Secondary indexing but in a restricted way, i.e., only equality queries, not always the best performing solution.	It supports Secondary indexing.
9.	It does not supports Server-side scripting.	It has user defined functions for Server-side scripts.
10.	It supports selectable replication factor method.	It supports Master-master replication method.
11.	In Cassandra, partitioning can be done Sharding.	In PostgreSQL, partitioning can be done by range, list and hash.
12.	It offers an API for user-defined Map/Reduce methods.	It does not offers an API for user-defined Map/Reduce method.
13.	Cassandra does not provides the concept of Referential Integrity. Hence, no Foreign Keys.	PostgreSQL provides the concept of Referential Integrity and have Foreign keys.