The Oracle system has latch free wait events and runs ultra-long SQL monitoring analysis.

1. latch free wait event SQL:

Select *
From v $ session_wait t
Where t. EVENT not in
('SQL * Net message from client', 'rdbms ipc message ',
'SQL * Net more data from client',' SQL * Net more data to client ',
'SQL * Net message to client', 'jobq slave wait ')

Result Analysis Description: Check whether there are latch and enqueue events in the query results. If so, find the HASHVALUE of SQL based on the sid.

2. Run an SQL monitoring SQL statement that is too long:

Select * from v $ session_longops a where a. time_remaining> 0

Result Analysis Description: it is costly to find a full table scan or hash jion. You need to find hash_value, and then go to v $ sqltext to find the specific statement for optimization!