Default: none.
-=item -N, --skip-artnum
+=item --skip-artnum
This option allows archivists to publish incomplete archives
with only new mail while allowing NNTP article numbers
Control the number of Xapian index shards in a
C<-V2> (L<public-inbox-v2-format(5)>) inbox.
-It is useful to use a single shard (C<-j1>) for inboxes on
+It can be useful to use a single shard (C<-j1>) for inboxes on
high-latency storage (e.g. rotational HDD) unless the system has
enough RAM to cache 5-10x the size of the git repository.
-It is generally not useful to specify higher values than the
-default due to contention in the top-level producer process.
+Another approach for HDDs is to use the
+L<public-inbox-index(1)/publicInbox.indexSequentialShard> option
+and many shards, so each shard may fit into the kernel page
+cache. Unfortunately, excessive shards slows down read-only
+query performance.
-Default: the number of online CPUs, up to 4
+For fast storage, it is generally not useful to specify higher
+values than the default due to the top-level producer process
+being a bottleneck.
+
+Default: the number of online CPUs, up to 4 (3 shard workers, 1 producer)
+
+=item --skip-docdata
+
+Do not store document data in Xapian, reducing Xapian storage
+overhead by around 1.5%.
+
+Warning: this option prevents rollbacks to public-inbox 1.5.0
+and earlier.
+
+Available since public-inbox 1.6.0 (PENDING).
=back