The Oracle and PL/SQL SYS_CONTEXT function return information about the Oracle environment.
The general format is:
SYS_CONTEXT(namespace,param,[length])
Example 1:
select sys_context('USERENV', 'DB_NAME') from dual;
returns:
mydatabase
Example 2:
SELECT sys_context('USERENV', 'NLS_CURRENCY') FROM DUAL;
returns:
$