Hello Everyone,
Just One day before one Developer told me that my application hangs too much. So when it hangs next time I queried v$session and in the event I found 'enq: TM - contention'. So I google this event and I found that there is a locking issue of table. So making an index in the foreign key column will solve your problem and problem is solved.
But I want to know How index comes into the picture ? What index actually doing that cause my issue to be resolved.
Please help me out to understand this.