1. 微软 SQL 服务器：
Microsoft SQL Server 是一个关系数据库管理系统 (RDBMS)，它依赖于平台，并且是基于 GUI 和命令的软件。它支持企业 IT 环境中的各种事务处理、商业智能和分析应用程序。它由微软公司开发，最初于 1989 年 4 月 24 日发布。
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。它是第一个实现多版本并发控制 (MVCC) 功能的 DBMS。
MS SQL Server 和 PostgreSQL 的区别：
| S.NO. | MS SQL SERVER | POSTGRESQL |
|---|---|---|
| 1. | Developed by Microsoft Corporation and initially released on April 24, 1989 | Developed by PostgreSQL Global Development Group on 1989. |
| 2. | MS SQL server is written in C++ language. | PostgreSQL is written in C language. |
| 3. | It is a Microsoft relational DBMS. | It is widely used open source RDBMS. |
| 4. | The primary database model for MS SQL Server is Relational DBMS. | The primary database model for PostgreSQL is also Relational DBMS. |
| 5. | It also has two Secondary database models – Document store and Graph DBMS. | It has Document store as Secondary database models. |
| 6. | The license for MS SQL Server is Commercial. | The license for is Open Source. |
| 7. | Server operating systems for MS SQL Server are Linux and Windows. | Server operating systems for PostgreSQL are FreeBSD, HP-UX, Linux, NetBSD, OpenBSD, OS X, Solaris, Unix and Windows. |
| 8. | In MS SQL Server, partitioning methods are Horizontal partitioning and Sharding through federation. | In PostgreSQL, partitioning can be done by range, list and hash. |
| 9. | It support replication but in depends on the SQL-Server Edition. | It support only one replication methods – Master-master replication. |
| 10. | It supports in-memory capabilities. | It does not supports in-memory capabilities. |