Re: [ROOT] Slow down in reading TTree

From: Rene Brun (Rene.Brun@cern.ch)
Date: Wed May 14 2003 - 18:04:03 MEST


Hi Victor,

Please provide more information!
Do you see this slow down only for a few branches or for any branches, all
branches?
Could you activate gDebug=2 when reading with 3.03 and 3.05?
Could you send the output of 
file->ShowStreamerInfo();

Rene Brun

> Victor Perevoztchikov wrote:
> 
> Dear rooter,
> during transition from ROOT 3.03.09 ==> 3.05.04 in STAR experiment
> we found that reading of TTree is 2.5 times slower in new version.
> Timong
> 3.03.09: Real: 38.42 CPU: 36.93
> 3.05.04  Real: 93.94 CPU: 93.21
> DST was produced by ROOT 3.03.09
> Reading a few branches from big TTree
> 
> 
> Any ideas why?
> May be old format is still supported but slowly?
> 
> 
> Victor
> 
> 
> Victor M. Perevoztchikov   perev@bnl.gov
> Brookhaven National Laboratory MS 510A PO Box 5000 Upton NY 11973-5000
> tel office : 631-344-7894; fax 631-344-4206;



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