Data Dictionary View
Columns ___________________________ INSTANCE_NUMBER INSTANCE_NAME HOST_NAME VERSION STARTUP_TIME STATUS PARALLEL THREAD# ARCHIVER LOG_SWITCH_WAIT LOGINS SHUTDOWN_PENDING DATABASE_STATUS INSTANCE_ROLE (Primary or secondary instance) ACTIVE_STATE
Related:
V$ACTIVE_INSTANCES V$BGPROCESS V$BH V$COMPATIBILITY V$COMPATSEG V$COPY_CORRUPTION V$DATABASE V$DATAFILE V$DATAFILE_COPY V$DATAFILE_HEADER V$DBFILE V$DBLINK V$DB_PIPES V$LICENSE V$OFFLINE_RANGE V$OPTION V$SGA V$SGASTAT V$TABLESPACE V$VERSION
dbms_utility.db_version