When these flags are specified, the object names recorded
for the paths are not updated. Instead, these options
set and unset the "assume unchanged" bit for the
- paths. When the "assume unchanged" bit is on, git stops
+ paths. When the "assume unchanged" bit is on, Git stops
checking the working tree files for possible
modifications, so you need to manually unset the bit to
- tell git when you change the working tree file. This is
+ tell Git when you change the working tree file. This is
sometimes helpful when working with a big project on a
filesystem that has very slow lstat(2) system call
(e.g. cifs).
--index-version <n>::
Write the resulting index out in the named on-disk format version.
- The current default version is 2.
+ Supported versions are 2, 3 and 4. The current default version is 2
+ or 3, depending on whether extra features are used, such as
+ `git add -N`.
++
+Version 4 performs a simple pathname compression that reduces index
+size by 30%-50% on large repositories, which results in faster load
+time. Version 4 is relatively young (first released in in 1.8.0 in
+October 2012). Other Git implementations such as JGit and libgit2
+may not support it yet.
-z::
Only meaningful with `--stdin` or `--index-info`; paths are
Using ``assume unchanged'' bit
------------------------------
-Many operations in git depend on your filesystem to have an
+Many operations in Git depend on your filesystem to have an
efficient `lstat(2)` implementation, so that `st_mtime`
information for working tree files can be cheaply checked to see
if the file contents have changed from the version recorded in
the index file. Unfortunately, some filesystems have
inefficient `lstat(2)`. If your filesystem is one of them, you
can set "assume unchanged" bit to paths you have not changed to
-cause git not to do this check. Note that setting this bit on a
-path does not mean git will check the contents of the file to
-see if it has changed -- it makes git to omit any checking and
+cause Git not to do this check. Note that setting this bit on a
+path does not mean Git will check the contents of the file to
+see if it has changed -- it makes Git to omit any checking and
assume it has *not* changed. When you make changes to working
-tree files, you have to explicitly tell git about it by dropping
+tree files, you have to explicitly tell Git about it by dropping
"assume unchanged" bit, either before or after you modify them.
In order to set "assume unchanged" bit, use `--assume-unchanged`
The command looks at `core.ignorestat` configuration variable. When
this is true, paths updated with `git update-index paths...` and
-paths updated with other git commands that update both index and
+paths updated with other Git commands that update both index and
working tree (e.g. 'git apply --index', 'git checkout-index -u',
and 'git read-tree -u') are automatically marked as "assume
unchanged". Note that "assume unchanged" bit is *not* set if