Hello,
i was analyzing an AWR report of production DB, and found that Rollback per transaction is pretty high.
DB - 10g RAC, over Solaris 10.
DB Name DB Id Instance Inst num Release RAC Host
DBPROD 750237439 dbprod1 1 10.2.0.4.0 YES xyz
Snap Id Snap Time Sessions Cursors/Session
Begin Snap: 23273 01-Dec-10 10:00:09 93 4.3
End Snap: 23274 01-Dec-10 11:00:15 93 3.6
Elapsed: 60.10 (mins)
DB Time: 74.07 (mins)
Rollback per transaction %: 97.90
Now, while further digging into it, i analyzed
Total / sec / Tr
user rollbacks 3,636 1.01 0.98
And moreover - undo records applied 0 and transaction rollbacks 0.
So, as per my understanding this Rollback / transaction is not user initiated.
2 more things i'd like highlight -
While this AWR report was running, NO DML operation performed on the DB. however lot of SELECT stats, Procs and Packages executed and all contains only SELECT stats.
This application is not been connected to any web-server.
Please guide me in this scenario how such a high Rollback per Transaction % is high? And does it impacting DB performance?