Merge branch 'tl/midx-docfix'

[thirdparty/git.git] / Documentation / technical / multi-pack-index.txt

diff --git a/Documentation/technical/multi-pack-index.txt b/Documentation/technical/multi-pack-index.txt
index f14361d2c1e14aae34bdd878e175bdaf10570183..ba7e329019ef74351242a2c6a356a60f60989e40 100644 (file)
--- a/Documentation/technical/multi-pack-index.txt
+++ b/Documentation/technical/multi-pack-index.txt
@@ -36,15 +36,18 @@ Design Details
   directory of an alternate. It refers only to packfiles in that
   same directory.
 
-- The core.multiPackIndex config setting must be on to consume MIDX files.
+- The core.multiPackIndex config setting must be on (which is the
+  default) to consume MIDX files.  Setting it to `false` prevents
+  Git from reading a MIDX file, even if one exists.
 
 - The file format includes parameters for the object ID hash
   function, so a future change of hash algorithm does not require
   a change in format.
 
 - The MIDX keeps only one record per object ID. If an object appears
-  in multiple packfiles, then the MIDX selects the copy in the most-
-  recently modified packfile.
+  in multiple packfiles, then the MIDX selects the copy in the
+  preferred packfile, otherwise selecting from the most-recently
+  modified packfile.
 
 - If there exist packfiles in the pack directory not registered in
   the MIDX, then those packfiles are loaded into the `packed_git`
@@ -70,14 +73,10 @@ Future Work
   still reducing the number of binary searches required for object
   lookups.
 
-- The reachability bitmap is currently paired directly with a single
-  packfile, using the pack-order as the object order to hopefully
-  compress the bitmaps well using run-length encoding. This could be
-  extended to pair a reachability bitmap with a multi-pack-index. If
-  the multi-pack-index is extended to store a "stable object order"
+- If the multi-pack-index is extended to store a "stable object order"
   (a function Order(hash) = integer that is constant for a given hash,
-  even as the multi-pack-index is updated) then a reachability bitmap
-  could point to a multi-pack-index and be updated independently.
+  even as the multi-pack-index is updated) then MIDX bitmaps could be
+  updated independently of the MIDX.
 
 - Packfiles can be marked as "special" using empty files that share
   the initial name but replace ".pack" with ".keep" or ".promisor".