ROOT memory usage

Peter Steinberg (steinber@nevis1.nevis.columbia.edu)
Fri, 29 May 1998 22:08:12 -0400 (EDT)

I have a ROOT tree that is about 6MB compressed, and maybe 15MB
uncompressed (although I don't remember exactly how big at the moment).
Now whenever I try to simply define the branches in order to read in
events (i.e. I execute the code produced by TTree::MakeCode()) ROOT seems
to want to unpack the whole thing into memory. Usually this is fine, but
when I try to use it on my 32MB home PC (linux or windows) it just swaps
incessantly and I never get the prompt again.

Thus, my question is: Is there a parameter I can tune in the reading or
writing to make a more memory-friendly tree?

Thanks,
Peter

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Peter Steinberg, Columbia University E-mail: peter.steinberg@cern.ch
Nevis Laboratories URL: http://wwwcn.cern.ch/~steinber
P.O. Box 137 Home Phone: (212)678-5971
Irvington, NY 10533
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