Consider a hypothetical archive format that does the following under the covers, given a list of files to pack:
- gzip each file individually
- Tar the gzips together
Contrast this with traditional tar followed by gzip.
Under what circumstances, if any, would the former method result in better compression than the latter?
A friendly implementation of the former method would allow quicker access to individual packed files, as well as immediate access to the index. So I am wondering about the conditions under which these advantages are offset by a potential reduction in compression due to not considering the stream of content as a whole.