To show the name of the session compute group, use the HELP SESSION statement. For example:
HELP SESSION;
*** Help information returned. One row.
User Name DBC
Account Name DBC Logon Date 21/01/14
Logon Time 08:15:16 Current DataBase DBC
Collation ASCII
Character Set ASCII
...
...
SearchUDFDBPath ?
SearchUDFUDFPath ?
CurrentCogGroup ShippingGrp