j Thanks

Hipkiss Thank you

Chris Armstrong Thank you

Thanks, second question is basically how to differentiate whether call is made by user or some kind of program like a for - loop and making continuous calls.

Thank you Francisco M. Santana Verona

Thanks Marco Alka . Do you have idea how Continuous Query Notification works in Oracle with Java, will there be any performance or any other implications if I try to follow it.

I do have service layer but as you said data is from other source getting pushed into tables. Oracle do provide something called Continuous Query Notification , but I'm not sure what will be the performance hit/ will there be any other implications if I do it.

I'm using Heroku. It's free version gives you around 750Hrs per month

No, its not. Spring container just creates object for you. It's your responsibility to make it thread safe.

yup. It's just for testing DI :)