RooFit: Roodataset size limit?

I have a very simple script which doesn’t seem to complete:

TFile fq("…/…/rootfiles/pi0pi01to6.root");
using namespace RooFit;

TTree *txCCBar = fq.Get(“ccbar”);
RooRealVar delMass(“delMass”, “delMass”, 0.139, 0.141, “d”);
RooArgList lsBase(delMass);
RooDataSet dsCCBarAll(“dsCCBarAll”, “dsCCBarAll”, txCCBar, lsBase);

Using this procedure with a 1.6gig file it seems to work, with a 2.3gig file it doesn’t seem to complete. I’m not completely sure it has anything to do with filesize, as these two root files were assembled in slightly different ways, but it’s the only thing that jumps out at me.

Thanks for any help you can give,

Hi James,

I assume that your tree has many observables and that you’re not trying to load 2.3
GB of data in memory (RooDataSets are memory resident, but only copy the relevant branches of the input tree to memory).

To understand more of this I’d either need access to your file (I can access files on CERN, don’t know if that works for you) or you should attach a debugger to your root session yourself to see where it is in the code once you’re stuck and post that here.