ROOT I/O Meeting

Friday 4 Oct 2019, 16:00 → 17:40 Europe/Zurich

32/1-A24 (CERN)

Brian Paul Bockelman (University of Nebraska-Lincoln (US)), Philippe Canal (Fermi National Accelerator Lab. (US))

Attendees: Philippe, Oksana, Jim, Pratyush Das, Jakob

Oksana: update on the presentation.  ZSTD seems useful for CMS miniaod.

Jim: Working on Awkward array

Jakob: Started building virtual prop station for RNTuple. .. implementing sample analysis in 3 different ways (SetBranchAddress, RNtuple direct, RNtuple view, RDataFrame). DImuon spectrum on CMS miniaod.  LHCb examples.  H1 tutorials (h1 micro DST files).  Collecting size with various compression.   Running time depending on fraction of columns read.   See https://github.com/jblomer/iotools/tree/calibration and https://github.com/jblomer/root/tree/ntuple-chep19.  I will present some preliminary result next week.   Dimon helping me with example setup and chain implementation.

Pratyush: Faster connection to NumpyArray and output TTree in uproot via slicing.

Philippe: resolved sad, very sad memory leak in reading uncompressed TTree.   We need to add valgrind (or whatever) leak check in our test suite.

Philippe: working on hadd tear down speed and ROOT collection with duplicate element.

Philippe: Next meeting on Friday October 11.
 

16:00 → 16:20 Round Table