Autogenerated HTML docs for v2.12.0-399-g9d77b 
diff --git a/git-update-index.txt b/git-update-index.txt index 7386c93..1579abf 100644 --- a/git-update-index.txt +++ b/git-update-index.txt 
@@ -163,14 +163,16 @@    --split-index::  --no-split-index:: -	Enable or disable split index mode. If enabled, the index is -	split into two files, $GIT_DIR/index and $GIT_DIR/sharedindex.<SHA-1>. -	Changes are accumulated in $GIT_DIR/index while the shared -	index file contains all index entries stays unchanged. If -	split-index mode is already enabled and `--split-index` is -	given again, all changes in $GIT_DIR/index are pushed back to -	the shared index file. This mode is designed for very large -	indexes that take a significant amount of time to read or write. +	Enable or disable split index mode. If split-index mode is +	already enabled and `--split-index` is given again, all +	changes in $GIT_DIR/index are pushed back to the shared index +	file. ++ +These options take effect whatever the value of the `core.splitIndex` +configuration variable (see linkgit:git-config[1]). But a warning is +emitted when the change goes against the configured value, as the +configured value will take effect next time the index is read and this +will remove the intended effect of the option.    --untracked-cache::  --no-untracked-cache:: @@ -388,6 +390,31 @@  different from assume-unchanged bit's. Skip-worktree also takes  precedence over assume-unchanged bit when both are set.   +Split index +----------- + +This mode is designed for repositories with very large indexes, and +aims at reducing the time it takes to repeatedly write these indexes. + +In this mode, the index is split into two files, $GIT_DIR/index and +$GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in +$GIT_DIR/index, the split index, while the shared index file contains +all index entries and stays unchanged. + +All changes in the split index are pushed back to the shared index +file when the number of entries in the split index reaches a level +specified by the splitIndex.maxPercentChange config variable (see +linkgit:git-config[1]). + +Each time a new shared index file is created, the old shared index +files are deleted if their modification time is older than what is +specified by the splitIndex.sharedIndexExpire config variable (see +linkgit:git-config[1]). + +To avoid deleting a shared index file that is still used, its +modification time is updated to the current time everytime a new split +index based on the shared index file is either created or read from. +  Untracked cache  ---------------