public-inbox-xcpdb is similar to L<copydatabase(1)> for
upgrading to the latest database format supported by Xapian
(e.g. "glass" or "honey"), but is designed to tolerate and
-recover from Xapian database modifications from
-L<public-inbox-watch(1)> or L<public-inbox-mda(1)>.
+accept parallel Xapian database modifications from
+L<public-inbox-watch(1)>, L<public-inbox-mda(1)>,
+L<public-inbox-learn(1)>, and L<public-inbox-index(1)>.
=head1 OPTIONS
In particular, it DOES NOT upgrade the schema used by the
PSGI search interface (see L<public-inbox-index(1)>).
+=head1 LIMITATIONS
+
+Do not use L<public-inbox-purge(1)> or L<public-inbox-edit(1)>
+while this is running; old (purged or edited data) may show up.
+
+Normal invocations L<public-inbox-index(1)> can safely run
+while this is running, too. However, reindexing via the
+L<public-inbox-index(1)/--reindex> switch will be a waste of
+computing resources.
+
=head1 CONTACT
Feedback welcome via plain-text mail to L<mailto:meta@public-inbox.org>