Here are the examples of Oracle SQL queries to check user permissions.

Check Current User Permissions in Oracle

If you want to check the user permissions for the currently logged in user, run the following SQL queries:

select * from USER_ROLE_PRIVS where USERNAME=USER;
select * from USER_TAB_PRIVS where Grantee = USER;
select * from USER_SYS_PRIVS where USERNAME = USER;

To check the permissions for other users, you can run the following Oracle SQL queries:

To check the roles granted to a user:

SELECT * 
  FROM DBA_ROLE_PRIVS 
  WHERE GRANTEE = 'USERNAME';

Permissions already have:

SELECT * 
  FROM DBA_TAB_PRIVS 
  WHERE GRANTEE = 'USERNAME';

System privileges granted:

SELECT * 
  FROM DBA_SYS_PRIVS 
  WHERE GRANTEE = 'USERNAME';