Hi Garjola,
from what I can read, ROOT seems to be a perfect match for you. @amadio is right: you can always resort to the columnar storage of root, being it a TTree or a TNtuple. One way, which is the one I would suggest, is to resort to the TDataFrame, as I suggested in this other post: Convert SQLite Database into ROOT TTree
While there we are discussing a conversion from SQL to CSV and then analyse with ROOT, one could even think, thanks to the ROOT TSQLFile class, to write a TDataSource to read directly from SQL files.
Cheers,
Danilo