Reading directly a ROOT file from https is very slow, comparing to downloading it and using it locally.
As test I am doing a very simple plot
Electrons_All->Draw("pt__NOSYS")
If I open the file from https directly, e.g. with
root -l https://cernbox.cern.ch/remote.php/dav/public-files/ntHJKDVRTjlSkyS/test_ntuples_200123.root
making the plots takes ~5 minutes (the ntuple is very small, 60k events).
On the contrary, if I download it it takes ~0s to make the plot. To download it with wget it take 0.6s (4.5MB)
wget https://cernbox.cern.ch/remote.php/dav/public-files/ntHJKDVRTjlSkyS/test_ntuples_200123.root
root -l test_ntuples_200123.root
ROOT Version: 6.26/10
Platform: Linux fedora 6.0.18-300.fc37.x86_64
Compiler: gcc 12.2.1