(oracle) why user has not [alter session] privilege but can alter session-CodePudding

the question is as the title
at the oracle19c
why a user that only has [create session]privilege,but it can alter session like this:
step1:sqlplus / as sysdba
create user TESTUSER identified by TESTUSER;
grant create session to TESTUSER;
step2:sqlplus TESTUSER/TESTUSER
ALTER SESSION SET NLS_TIMESTAMP_FORMAT = 'SYYYY-MM-DD HH24:MI:SS.FF9';
(why this user can alter session succussfully?)

CodePudding user response：

From the documentation: https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/ALTER-SESSION.html#GUID-27186B28-7EFC-4998-B1ED-2B905CC0211B

Prerequisites

To enable and disable the SQL trace facility, you must have ALTER SESSION system privilege.

To enable or disable resumable space allocation, you must have the RESUMABLE system privilege.

You do not need any privileges to perform the other operations of this statement unless otherwise indicated.