Hi, > > Hi Andre, > > Sorry to answer only now this old mail from you. no problem...I wonder anyhow how so few people (root programmes) can answer so many requests a day... > > The TTree::Query function returns a TTreeResult object that holds the > result of your query (all rows and columns). This may be a very large object. > In the version 3.02/06 recently released, the Query function has been > drastically > improved in time (about a factor 8 in your example) and the space in memory > used to store the result divided by about two. This has been achieved > by rewriting the class TTreeRow. thanks ! Indeed, yesterday evening (with a pre-3.02/06 version), in a specific case (accessing 36 variables per event where the largest number of events selected in a query is about 220'000), the memory usage (resident set size) became stationary at about 210 MB, now I tested it with the newest root version from CVS and the same number is about 155 MB (this includes of course also other memory unrelated to the Query() ). thanks & best regards, André -- ------------------+---------------------------------- Andre Holzner | +41 22 76 76750 Bureau 32 2-C13 | Building 32 CERN | Office 2-C13 CH-1211 Geneve 23 | http://wwweth.cern.ch/~holzner/
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