Too many open files with TChain

Hello fellow rooters,

I’m running into a problem loading multiple large TChains. For each run, I am friending together several (~50) TChains that are spread across 7 files. When I try to add ~200 series to the chains and then do any kind of command, I get lots of “too many open files” messages.

Do TChains intellgently manage their files at all? I.e., do they close each file during the Draw loop once it has processed that tree? If so, then I don’t understand why I would be seeing this error.
Or do they leave open all the associated files, in which case I guess there’s not much I can do?

Many thanks,