Low performance merging files with RDataFrame plus multiple cycles

[Wile_E_Coyote]

I guess, you will get “equal” speeds, if you try:

    mrg=ROOT.TFileMerger(True)
    mrg.SetFastMethod(False)

BTW. See:

Aux;1 aux;2 aux3;

Search for “cycle” and/or “namecycle”, for example in: In a Nutshell: Input and Output . ROOT User’s Guide: Input/Output : Retrieving Objects from Disk , Subdirectories and Navigation . Just for reference: some additional notes about GetObject, Get, FindObjectAny, FindKeyAny, ReadObj, ReadObjAny .