Active Session History (ASH)
Good Day Guys,
We installed Oracle Database 12c in our production environment, recently I found the following statement in database alertlog.
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 16777216 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$ash_info;
By running the said query it shows the following result, now my question is how to adjust ASH size? does it gives big impact on the database performance?
We installed Oracle Database 12c in our production environment, recently I found the following statement in database alertlog.
Active Session History (ASH) performed an emergency flush. This may mean that ASH is undersized.
If emergency flushes are a recurring issue, you may consider increasing ASH size by setting the value of _ASH_SIZE to a sufficiently large value.
Currently, ASH size is 16777216 bytes. Both ASH size and the total number of emergency flushes since instance startup can be monitored by running the following query:
select total_size,awr_flush_emergency_count from v$ash_info;
By running the said query it shows the following result, now my question is how to adjust ASH size? does it gives big impact on the database performance?
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