Both keys and values in FoundationDB are simple byte strings and keys are treated as members of a total order, the lexicographic order over the underlying bytes

Both keys and values in FoundationDB are simple byte strings and keys are treated as members of a total order, the lexicographic order over the underlying bytes, in which keys are sorted by each byte in order. You can see some more details about it here: https://apple.github.io/foundationdb/data-modeling.html https://apple.github.io/foundationdb/data-modeling.html