OperationFailed: Sort operation used more than the maximum XXX bytes of RAM. Add an index, or specify a smaller limit. This can happen because of a bug like SERVER-13611 (so make sure you are on the latest version), or because you are trying to sort on a sparse index in 2.6, but more usually it…Continue reading OperationFailed: Sort operation used more than the maximum XXX bytes of RAM. Add an index, or specify a smaller limit.