I’m having an issue where the root files I build as a result of a TTree-based analysis are not being compressed. If I check the compression of the tree with a tree->Print(), each branch and the total tree return a compression factor of 1.00. Previous analysis of similar data have yielded compression factors of > 15. If I manually specify a compression level or compression settings prior to the TFile->Write() it seems to have no effect. I realize this is a somewhat vague question, but what things might prevent a TFile from being compressed?
ROOT Version: 6.12.06, 6.14.06
Platform: SL 6.4, MACOSX 10.14.1
Compiler: gcc4.8.2, Xcode