The oracle_sid is set
my oracle version is:

Oracle9i Release 9.0.1.0.0 - Production
PL/SQL Release 9.0.1.0.0 - Production
CORE 9.0.1.0.0 Production
TNS for Compaq Tru64 UNIX: Version 9.0.1.0.0 - Production
NLSRTL Version 9.0.1.0.0 - Production