An encoding method for multifield sorting and indexing

TLDR: An encoding scheme is described which produces a single, order-preserving string from a sequence of strings, useful for multifield sorting, multifield indexing, and other applications where ordering on more than one field is important.

Abstract: Sequences of character strings with an order relation imposed between sequences are considered. An encoding scheme is described which produces a single, order-preserving string from a sequence of strings. The original sequence can be recovered from the encoded string, and one sequence of strings precedes another if and only if the encoding of the first precedes the encoding of the second. The strings may be variable length, without a maximum length restriction, and no symbols need be reserved for control purposes. Hence any symbol may occur in any string. The scheme is useful for multifield sorting, multifield indexing, and other applications where ordering on more than one field is important.