index: support --rethread switch to fix old indices

[public-inbox.git] / Documentation / public-inbox-index.pod

diff --git a/Documentation/public-inbox-index.pod b/Documentation/public-inbox-index.pod
index 5be3c897bbf7f61d19d79403e08f32e740a76308..08f2fbf453228db0ac7bb917d7a9f5642e0a8c6a 100644 (file)
--- a/Documentation/public-inbox-index.pod
+++ b/Documentation/public-inbox-index.pod
@@ -32,6 +32,16 @@ normal search functionality.
 
 =over
 
+=item --jobs=JOBS, -j
+
+Control the number of Xapian indexing jobs in a
+(L<public-inbox-v2-format(5)>) inbox.
+
+C<--jobs=0> is accepted as of public-inbox 1.6.0 (PENDING)
+to disable parallel indexing.
+
+Default: the number of existing Xapian shards
+
 =item --compact / -c
 
 Compacts the Xapian DBs after indexing.  This is recommended
@@ -46,6 +56,8 @@ This switch may be specified twice, in which case compaction
 happens both before and after indexing to minimize the temporal
 footprint of the (re)indexing operation.
 
+Available since public-inbox 1.4.0.
+
 =item --reindex
 
 Forces a re-index of all messages in the inbox.
@@ -56,12 +68,25 @@ Xapian database.  Using this with C<--compact> or running
 L<public-inbox-compact(1)> afterwards is recommended to
 release free space.
 
-public-inbox protects writes to various indices with L<flock(2)>,
-so it is safe to reindex while L<public-inbox-watch(1)>,
-L<public-inbox-mda(1)> or L<public-inbox-learn(1)> run.
+public-inbox protects writes to various indices with
+L<flock(2)>, so it is safe to reindex (and rethread) while
+L<public-inbox-watch(1)>, L<public-inbox-mda(1)> or
+L<public-inbox-learn(1)> run.
+
+This does not touch the NNTP article number database.
+It does not affect threading unless C<--rethread> is
+used.
 
-This does not touch the NNTP article number database or
-affect threading.
+=item --rethread
+
+Regenerate internal THREADID and message thread associations
+when reindexing.
+
+This fixes some bugs in older versions of public-inbox.  While
+it is possible to use this without C<--reindex>, it makes little
+sense to do so.
+
+Available in public-inbox 1.6.0 (PENDING).
 
 =item --prune
 
@@ -70,18 +95,24 @@ is detected.  This is intended to be used in mirrors after running
 L<public-inbox-edit(1)> or L<public-inbox-purge(1)> to ensure data
 is expunged from mirrors.
 
+Available since public-inbox 1.2.0.
+
 =item --max-size SIZE
 
 Sets or overrides L</publicinbox.indexMaxSize> on a
 per-invocation basis.  See L</publicinbox.indexMaxSize>
 below.
 
+Available since public-inbox 1.5.0.
+
 =item --batch-size SIZE
 
 Sets or overrides L</publicinbox.indexBatchSize> on a
 per-invocation basis.  See L</publicinbox.indexBatchSize>
 below.
 
+Available in public-inbox 1.6.0 (PENDING).
+
 =back
 
 =head1 FILES