View state oracle database table

select a.status, b.open_mode from gv $ instance a, gv $ database b; (See status database)

select * from dba tablespace_usage_metrics order by USED_PERCENT desc; (see table space)

select inst id, count (*) from gv $ session group by inst_id; (check the database connections)

select total mb, free_mb, name from v $ asm_diskgroup; (view disk usage)

select event, count (*) from gv $ session group by event order by count (*); (see the current wait events)

select userenv ( 'language') from dual; (See server-side character set)