1. PouchDB：
PouchDB是一个开源的NoSQL嵌入式数据库。它是在CouchDB之后设计的，CouchDB是为npm提供支持的NoSQL数据库。它是用JavaScript语言编写的。由于PouchDB驻留在浏览器内部，因此无需通过网络执行查询，因此它使其速度非常快。它在浏览器中使用IndexedDB和WebSQL在本地存储数据。
2.卡桑德拉：
Cassandra是一个分布式数据库管理系统，它是开源的，具有宽列存储NoSQL数据库，该数据库旨在处理和支持许多服务器上的大量数据。它为我们提供了高可用性，没有单点故障。 Cassandra最初于2008年7月发布，由Apache Software Foundation开发。 PouchDB和Cassandra之间的区别：
| S.NO. | PouchDB | Cassandra |
|---|---|---|
| 1. | PouchDB was initially released in 2012 and was developed by Apache Software Foundation. | Cassandra was initially released in July 2008 and was developed by Apache Software Foundation. |
| 2. | PouchDB is written using Javascript language. | Cassandra is written only in Java language. |
| 3. | PouchDB is server-less. It requires a JavaScript environment (browser, Node.js). | Cassandra server operating systems are BSD, Linux, OS X and Windows. |
| 4. | PouchDB supports JavaScript programming language. | Cassandra supports programming languages like C#, C++, Clojure, Erlang, Go, Haskell, Java, JavaScript, Perl, PHP, Python, Ruby and Scala. |
| 5. | PouchDB only provides Eventual Consistency method to ensure consistency in a distributed system. | Cassandra provides us with Eventual Consistency and Immediate Consistency method to ensure consistency in a distributed system. |
| 6. | PouchDB has no predefined datatypes. | Cassandra has predefined datatypes such as float, date, etc. |
| 7. | In PouchDB, access rights for users cannot be defined. | In Cassandra, access rights for users can be defined per object. |
| 8. | PouchDB supports both Master-Slave Replication and Master-Master Replication. | Cassandra supports Selectable Replication Factor replication method. |
| 9. | PouchDB supports the secondary indexes without any restrictions. | Secondary indexes in Cassandra is restricted. |
| 10. | Some companies like GenCorp Technologies, Akamai Technologies, Hothead Games Inc., Vivint Solar, etc use PouchDB. | Some companies like Instagram, Reddit, GitHub, Hulu, The Weather Channel, etc use Cassandra. |