Hot block contention caused by frequently changing table invalid indexes
There is an alarm of ultra-high number of session connections in the customer number management system, which causes database performance problems and affects the business processing of the whole network. The alarm occurred between 20:00 and 21:00 on November 7. Check the buffer busy waits with the highest waiting time at that time.
Query the sql corresponding to the waiting event
Select sql_id, count (*)
From v$active_session_history
Where sample_time > =
To_date ('2016-11-07 20-00 to_date,' yyyy-mm-dd hh34:mi:ss')
And sample_time =
To_date ('2016-11-07 20-00 to_date,' yyyy-mm-dd hh34:mi:ss')
And sample_time =
To_date ('2016-11-07 20-00 to_date,' yyyy-mm-dd hh34:mi:ss')
And sample_time
