Priority: Major - P3
Affects Version/s: None
Fix Version/s: None
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Last comment by Customer:true
I think this line is wrong:
Collections expire by way of a special index that keeps track of insertion time in conjunction with a background thread in mongod that regularly removes expired documents from the collection.
The index is on the field you specify, I don't think there's any tracking of insertion time unless it's changed since the last time I looked at the code (circa March'13).