implications of unsorted TChain indices

Hi all,

   I have a TChain that I create from a series of TTrees. I then use:

   fMetaChain->BuildIndex("metakey");

so that I can later pull the right entry by using:

   fMetaChain->GetEntryWithIndex(metakey);

When constructing the indices I'm getting:

Error in <TChainIndex::TChainIndex>: The indices in files of this chain aren't sorted.

I can believe that the indices aren't sorted relative to the order that trees are added to the chain. I'm wondering though whether this is just a warning indicative of possible poor performance or will the GetEntryWithIndex() fail to deliver the right entry? The chain is relatively short (~100's to ~1000's at max) and new entries aren't fetched very frequently so falling back to a straight linear search would be acceptable. But what the application can't abide would be to not get the right entry.

So, what is this "error" telling me?

Thanks,
-robert

Robert W. Hatcher | rhatcher_at_fnal.gov 630-840-3102 FNAL CD/REX (MINOS) | MS 220, PO Box 500, Batavia IL 60510 Received on Wed Mar 10 2010 - 16:05:58 CET