public-inboxes where cross-posting is common, this allows
significant space savings on Xapian indices.
+=item --dedupe=MSGID
+
+=item --dedupe
+
+Rerun deduplication on messages with the given Message-ID or
+all messages if no Message-ID is specified. Deduplication rules may
+change and evolve over time, especially if filters are involved.
+
+C<--dedupe=MSGID> may be specified multiple times to deduplicate
+multiple Message-IDs.
+
+Use this if you see C<W: BUG? $MSGID not deduplicated properly>
+warnings from WWW logs.
+
=item --gc
Perform garbage collection instead of indexing. Use this if
processes are utilizing the index. Keep in mind this roughly
doubles the size of the already-large Xapian database.
-The extindex locks will be released roughly every 10s to
-allow L<public-inbox-mda(1)> and L<public-inbox-watch(1)>
-processes to write to the extindex.
-
=item --fast
Used with C<--reindex>, it will only look for new and stale
Occasionally, public-inbox will update its schema version and
require a full index by running this command.
+=head1 LOCKING
+
+It is safe to use C<--dedupe>, C<--gc> and C<--reindex> while
+other processes are writing to covered inboxes or extindex.
+The extindex locks will be released roughly every 10s to
+allow L<public-inbox-mda(1)> and L<public-inbox-watch(1)>
+processes to write to the extindex.
+
=head1 CONTACT
Feedback welcome via plain-text mail to L<mailto:meta@public-inbox.org>