详细监控Oracle数据区域DG状态。

简介：
The following database status metrics are being examined: `on,status,database_status from v$instance`; the current operational mode, as retrieved from `mode from v$database`; the status of the control file, accessed via `controlfile`; and the member information of the redo log files, obtained through `member from v$logfile`. Furthermore, the destination status for archived data is investigated using `atabase_mode,destination from v$archive_dest_sta`. The number of days the database has been continuously running is determined by selecting `|| days from(select sysdate a` from the query. Additionally, session activity is monitored through metrics such as the high-water mark for active sessions (`sessions_highwater from v$license`), providing a session count (`ssion count from v$session where status=ACTIVE`), and a total session count (`ssion count from v$session`). Finally, identifying the top 30 largest objects involves querying for names like `a35 a15 -----部分截断sql---`.