Oracle: DBA_HIST_ASH_SNAPSHOT

select
   asn.begin_interval_time,
   asn.end_interval_time,
   asn.bl_moved,
   asn.con_id,
   asn.dbid,
   asn.error_count,
   asn.flush_elapsed,
   asn.instance_number,
   asn.snap_flag,
   asn.snap_id,
   asn.snap_level,
   asn.snap_timezone,
   asn.startup_time,
   asn.status
from
   sys.dba_hist_ash_snapshot asn
order by
   asn.begin_interval_time desc;

select
   case when vdb.dbid = asn.dbid then '*' end e,
   asn.dbid,
   count(*)                     cnt,
   min(asn.begin_interval_time) min_t,
   max(asn.  end_interval_time) max_t
from
   v$database            vdb   cross join
   dba_hist_ash_snapshot asn
group by
   asn.dbid,
   vdb.dbid
;