I mean i have other RDBMS as front end and Vertica runs in the back doing all the hard work etc.
I don't understand that this means about the relationship between data on the other systems and data on Vertica. What is your overall data strategy? Do you have monolithic files lying around that need to get block loaded? Your complaint about Vertica update speed suggests you might have lots of small updates?
If you have big files, best practice is actually to load using vsql itself, with the file sitting on one of the Vertica nodes. That is the fastest, anyways. You can write a loader that streams the big files over JDBC from a remote machine. This is how my company does it, and it's reasonably fast.
If you have lots of small rows that you want to send in frequently, Vertica is not as good with this. We also do this, but it is way slower.