From: Junio C Hamano Date: Fri, 21 Feb 2014 17:36:14 GMT Subject: Re: git gc --aggressive led to about 40 times slower "git log --raw" Message-ID: In-Reply-To: Christian Jaeger writes: > Also, in "man git-gc" document --aggressive that it leads to slower > *read* performance after the gc, I remember having red that option's > docs when I ran it, and since it didn't mention that it makes reads > slower, I didn't expect it to, and thus didn't remember this as the > source of the problem when I noticed that things were slow. Good point. We would at least need such a documentation update to warn users. > (But, I took from the discussion that increasing the gzip window size > (?) would make things smaller anyway, so perhaps all that isn't even > necessary?) If you are talking about "--window" in "git repack --window=xxxx", that is not related to gzip. It is how many other "similar" objects an object will be tried to delta against to find a smallest delta that can represent it in the pack. Such a better delta, if found, can give you a packfile with a smaller depth that is as small as another packfile created with a larger depth, which is an overall win, and using a wider window is a way to achieve such a result.