1.适用于PolarDB的阿里云ApsaraDB：
ApsaraDB for PolarDB是与MySQL，PostgreSQL和Oracle兼容的云原生关系数据库。 ApsaraDB的架构在单个群集中支持5000台物理机。它是为需要快速性能，高并发性和自动伸缩的关键业务数据库应用程序而设计的。
2.亚马逊海王星：
Amazon Neptune是Amazon.com为云产品构建的快速，可靠的图形数据库。它是AWS(Amazon Web Services)的一部分。它于2017年11月29日宣布。它同时支持开源Apache TinkerPop Gremlin图形遍历语言。它允许用户使用通过AWS Key Management Service创建的密钥来加密数据库。
适用于PolarDB的阿里云ApsaraDB和Amazon Neptune之间的区别：
| S.NO. | Alibaba Cloud ApsaraDB for PolarDB | Amazon Neptune |
|---|---|---|
| 1. | Developed By Alibaba on August 2013. | Developed By Amazon on 2017. |
| 2. | It is a cloud-native relational database compatible with MySQL, PostgreSQL, and Oracle. | It is a fast, reliable graph database built for the cloud product by Amazon.com |
| 3. | The License of Alibaba Cloud ApsaraDB for PolarDB is commercial. | The License of Amazon Neptune is commercial. |
| 4. | In Alibaba Cloud ApsaraDB for PolarDB, Hosted server operating systems | In Amazon Neptune, Hosted server operating systems |
| 5. | Its primary database model is Relational DBMS. | Its Primary database model are Graph DBMS and RDF store. |
| 6. | It support the Server-side scripting. | It does not support the Server-side scripting. |
| 7. | There is only one partitioning methods – Sharding. | It does not support partitioning methods. |
| 8. | It supports SQL query language. | It does not supports SQL query language. |
| 9. | It support replication methods. | It support multi-availability zones high availability. |
| 10. | It provides the concept of Referential Integrity. Hence, there is Foreign Keys. | It provides the concept of Referential Integrity. Hence, there is Foreign Keys. |
| 11. | It does not offers an API for user-defined Map/Reduce methods. | It does not offers an API for user-defined Map/Reduce methods. |
| 12. | Programming languages supported are Java and Python. | Programming languages supported are C#, Go, Java, JavaScript, PHP, Python, Ruby and Scala. |