select a.status,b.open_mode from gv$instance a,gv$database b; (查看数据库状态)
select * from dba tablespace_usage_metrics order by USED_PERCENT desc ; (查看表空间)
select inst id,count(*) from gv$session group by inst_id; (查看数据库连接数)
select total mb,free_mb,name from v$asm_diskgroup; (查看磁盘使用率)
select event , count (*) from gv$session group by event order by count (*); (查看当前等待事件)
select userenv ('language') from dual; (查看server端字符集)