David Kaminsky wrote:I'd like to have a "merge trial" function which would tell me how much space will be saved by doing a particular merge.
David, that's an interesting suggestion. I've also had many requests for statistics about how much duplicate data is contained in each layer, and in the archive as a whole.
I've put off implementing any of these because the calculations required are rather expensive. It requires building a map of all the data references in the archive, then isolating those used by one layer but no others. The "Searching for free space" phase of the capture action that occurs following a merge is (essentially) the same calculation. As you've probably already experienced, that can be a very time consuming process—often requiring 10 minutes or more to complete.
Nevertheless, I've had enough requests for this kind of information that I'm considering implementing some form of free/duplicate space calculator in the browser. With multi-core CPUs and multi-GB RAM becoming the norm, maybe it will actually turn out to be a usable feature.