Who can connect and query standby instance ?

Hi

The question can be split in to 2.

1. Which OS user can connect using SQLPLUS into standby instance ? i.e. does he have to be at dba group as the primary group or  any group ?

2. which DB user can query the standby instance ? i.e Is only SYS can connect and query ? any other DB user ?

the tables/ view that we are querying are :

v$archive_gap

DBA_LOGSTDBY_LOG

system.logmnr_log$

system.logstdby$parameters

dba_logstdby_progress

v$archive_dest_status

v$database_incarnation

v$instance

v$log

v$dataguard_stats

thanks

Eyal