I found a comparison between SQL Server and Oracle on the Internet.

A good database is very important ., Provides some reference for you to select a database
This article compares SQL Server in some aspects.
Openness
SQL Server can only run on Windows. Reliability, security, and scaling critical business ., Without any openness, the operating system is more focused on desktop applications, and the NT Server is very limited. Unlike the stability of Unix systems, it is very important for small and medium enterprises to database. Moreover, Windows has been tested for a long time, especially when processing big data.
Oracle can be used on all major platforms. This allows you to select the most appropriate line (including windows ). A fully supported solution. Fully supports all industrial standards for developers. Adopt a fully open policy.
　
Scalability and concurrency

SQL Server
The parallel implementation and coexistence model are not mature. It is difficult for Oracle Parallel servers to share a group of nodes with clusters with high scalability. If Windows processes an increasing number of users and data volumes. Limited scalability. Work in a cluster to expand the window nt capability and provide high availability nt to meet requirements. Users can move the database to Unix.

Security
SQL Server
No security certificate is obtained.
Oracle Server
Obtain the highest level of ISO certification.

Performance

SQL Server
Poor performance when multiple users

Oracle
Highest performance, keeping world records of TPC-D and TPC-C under WindowsNT.

SQL Server
C/S structure. It only supports Windows users and can be connected using ADO, Dao, oledb, and ODBC.

Oracle
Multi-layer network computing supports multiple industrial standards and can be connected by network customers such as ODBC, JDBC, and OCI.

Easy to operate

SQL Server
Simple operation, but only graphic interface.

Oracle
Complex: provides both GUI and command lines, and operates the same way in Windows NT and UNIX.

Usage risks

SQL Server
The code that is completely rewritten goes through early products. Use requires a long-term test, continuous delay, and many fixed risks. It takes time to prove the function.

Oracle
Long development experience is fully backward compatible. It is widely used. There is no risk at all.