Jessica,
I would suggest on issues like this, to try TUNAs360 from Mauro Pagano, or
SNAPPER from Tanel Poder. Both free. I see SNAPPER more session centric, which
in your case that is all you needed. In the other hand, TUNAs360 is easier to
use and tells you more about other sessions, and more about the SQL that you
are executing on your resource-intensive session of interest.
Then, once you identify the SQL taking long, use SQLd360, which is also free
and also from Mauro. The benefit of these tools is that you can share the
output for others to help, and you can easily document your findings out of the
same output.
Carlos
On Apr 25, 2016, at 10:10 AM, Jessica Mason <jessica.masson85@xxxxxxxxx>
wrote:
Hello List,
Last week, I was involved in a production issue, where a data load job, which
normally takes few hours to complete, had been running for more than 48
hours. I tried to take the following systematic approach to identify the
cause -
Step 1 - Identify the session and started profiling it. All the time, the
session was on CPU.
Step 2 - To understand why the session was burning CPU, the v$sesstat view
was queried and below were the top statistics that were changing :
43126075162624 logical read bytes from cache
240440566773 table scan rows gotten
2632208820 session logical reads
2632206511 consistent gets
2632206511 consistent gets from cache
2632205708 consistent gets from cache (fastpath)
Step 3 - Next, I wanted to know the object ( table/index) against which these
logical IOs were happening so that I could focus on the operations, involving
these objects, in the execution plan but didn't know which view to query.
The above information could have saved us lot to time to identify the cause (
in this case, an unique index was dropped and Oracle was doing FTS on a table
which was referred 6 times in the query fetching million of records).
So, my questions to the list is that which v$ view should I have checked?
Or is there a better approach to troubleshoot such issues?
Thanks
JM
