Hi Harshal,

I'll happily try and help, but unfortunately, your explanation of the issue is too high level to provide specifics. 

Which environment are you performing the transform on? Assume non-Prod such as 'Dev'.

Ensure you've exported the Prod data from the table you're wishing to run the transform map on and import this onto Dev. (Export the xml for example).

Use the Dev environment for exactly this use case. Test different scenario's and logic against this data on Dev against this data to overcome errors. 

To answer your question directly, any errors should not actually perform an update/insert. You can view these errors in the import log after you've ran the transform.

To help others, please mark correct and/or helpful

Thanks,

Robbie