What is the best compression algorithm that allows random reads/writes in a file?

Question

What is the best compression algorithm that allows random reads/writes in a file?

I know that any adaptive compression algorithms would be out of the question.

Answer 1

A dictionary-based compression scheme, with each dictionary entry's code being encoded with the same size, will result in being able to begin reading at any multiple of the code size, and writes and updates are easy if the codes make no use of their context/neighbors.

If the encoding includes a way of distinguishing the start or end of codes then you do not need the codes to be the same length, and you can start reading anywhere in the middle of the file. This technique is more useful if you're reading from an unknown position in a stream.