Pragmatic Guide to Git

42	Doing Some Git Housekeeping

One of Git’s key advantages is its speed. Keeping it fast requires some tuning, however. The git gc command provides the tuning tool.

git gc performs several housecleaning tasks. First, it removes any “loose objects” in the repository over a certain age. All of those commits you remove via git rebase, git reset, and so on, are still tracked by Git; they’re just orphaned.

Second, it recalculates the deltas. Deltas are the differences between two pieces of content in the repository. Many times the first pass at creating the delta is not the most efficient. Recalculating the deltas with the help of hindsight allows Git to combine like deltas to reduce the size of the repository and decrease the time ...