Manage Deadlocks in Oracle | Oracle 12c Administration

[@asmarshaikh2959]

According to video, session B will get deadlock error but According to article, session A gets the error. Nice Explanation though :)

[@dbagenesis]

Hope you enjoyed it!

[@phanikumarstudies1032]

Thanks Arun.

[@prabinapradhan441]

Any other way to get the Deadlocks? suppose one process selecting the same records on that time marge into same record , will give same problem ? it yes what could be the solution.

[@dominiquefortin5345]

The statement that "a deadlock is symptom of a bad design" is a joke. You never had to code any complex concurrent code. When you code and know that a deadlock is possible in a design, you just have to make the code fail gracefully. Every 3 sec or so, the database will check every waiting transactions to see there are loops of locks between them. If it find some, it will choose one victim and throw an exception (ORA-00060) in the transaction and hope it will resolve itself. If that does not resolve the problem, when it check again it will throw a exception again. Too many deadlocks is generally because of a catastrophic event.