I found this message in alert_log what needs to be done your suggestion please.....
Active Session History (ASH) performed an emergency flush. This may mean that ASH is undersized. If emergency flushes are a recurring issue,
you may consider increasing ASH size by setting the value of _ASH_SIZE to a sufficiently large value. Currently, ASH size is 134217728 bytes.
Both ASH size and the total number of emergency flushes since instance startup can be monitored by running the following query:
select total_size,awr_flush_emergency_count from v$ash_info;
Some suggestion giv n following link ,
Can i follow as per the link ? or can i go for support team ?
Active Session History (ASH) performed an emergency flush. ASH Undersized ? « Tales From A Lazy Fat Oracle DBA