I do have a serious problem with SSMS 18.4(MSSQL) and Oracle Server(12 C), How could I use "Linked Server" from SSMS IDE to connect Oracle server database.

PS:

1. How to set roles "SYSDBA"
2. Please do me a favor to give me any slight clue, thanks.

Oracle client connect to Oracle Server data:

SSMS connect to Oracle Server data:

By the way I also use "SQLPLUS" to check tnsnames.ora file is okay or not but the answer is as following

1. sqlplus SYS/Oradoc_db1@DBNAME as SYSDBA <-- is okay
2. sqlplus SYS/Oradoc_db1@DBNAME <-- Error