Sorry for the late reply.
Yes, it is possible, PROOF fills a TQueryResult object that can be accessed via TProof::GetQueryResult.
See root.cern.ch/basic-processing#queryresult .
Thanks for you answer, it works perfectly but I have another question, as TProof::GetQueryResult retrieves the information about the last query, is there any method to retrieve information about the query during it’s execution ?
What I want to know is the evolution of the parameters every second.