diff --git a/Documentation/git-filter-branch.txt b/Documentation/git-filter-branch.txt index e4c8e82660..2eba627170 100644 --- a/Documentation/git-filter-branch.txt +++ b/Documentation/git-filter-branch.txt @@ -393,7 +393,7 @@ git filter-branch --index-filter \ Checklist for Shrinking a Repository ------------------------------------ -git-filter-branch is often used to get rid of a subset of files, +git-filter-branch can be used to get rid of a subset of files, usually with some combination of `--index-filter` and `--subdirectory-filter`. People expect the resulting repository to be smaller than the original, but you need a few more steps to @@ -429,6 +429,37 @@ warned. (or if your git-gc is not new enough to support arguments to `--prune`, use `git repack -ad; git prune` instead). +Notes +----- + +git-filter-branch allows you to make complex shell-scripted rewrites +of your Git history, but you probably don't need this flexibility if +you're simply _removing unwanted data_ like large files or passwords. +For those operations you may want to consider +link:http://rtyley.github.io/bfg-repo-cleaner/[The BFG Repo-Cleaner], +a JVM-based alternative to git-filter-branch, typically at least +10-50x faster for those use-cases, and with quite different +characteristics: + +* Any particular version of a file is cleaned exactly _once_. The BFG, + unlike git-filter-branch, does not give you the opportunity to + handle a file differently based on where or when it was committed + within your history. This constraint gives the core performance + benefit of The BFG, and is well-suited to the task of cleansing bad + data - you don't care _where_ the bad data is, you just want it + _gone_. + +* By default The BFG takes full advantage of multi-core machines, + cleansing commit file-trees in parallel. git-filter-branch cleans + commits sequentially (ie in a single-threaded manner), though it + _is_ possible to write filters that include their own parallellism, + in the scripts executed against each commit. + +* The link:http://rtyley.github.io/bfg-repo-cleaner/#examples[command options] + are much more restrictive than git-filter branch, and dedicated just + to the tasks of removing unwanted data- e.g: + `--strip-blobs-bigger-than 1M`. + GIT --- Part of the linkgit:git[1] suite