has_schema_privilege function

Hi,

I refered
http://www.postgresql.org/docs/8.4/static/functions-info.html#FUNCTIONS-INFO-ACCESS-TABLE
and
got to know that I can fetch the information about permissions on schema.

Below commands work fine:

SELECT has_schema_privilege('user1', 'mydb', 'USAGE');
SELECT has_schema_privilege('user1', 'mydb', 'CREATE');

...But I want to check whether user has ALL permissions or not. Below
doesn;t work.

SELECT has_schema_privilege('user1', 'mydb', 'ALL');

Do I have to check both USAGE and CREATE permissions to check ALL
permissions?

Thanks.