Hello Jeevitha,

I think that this posts will help you understand all cases about your doubts.

https://www.outsystems.com/help/ServiceStudio/9.0/default.htm#Using_Data/Handling_Transactions.htm

https://www.outsystems.com/forums/discussion/15171/connection-pooling-in-outsystems-platform/

https://www.outsystems.com/forums/discussion/13643/understanding-the-outsystems-session-model/

Regards.