doc: various updates to reflect current state

-index documentation avoid redundant v1 information and refers
readers to apropriate v1/v2 manpages.  Search::Xapian can also
be optional, now, as only the PSGI search interface uses it.

Favor "INBOX_DIR" where appropriate, since "REPO_DIR" can be
confused for code repos which we also support.

XAPIAN_FLUSH_THRESHOLD is documented for all relevant
bulk commands.

1 files changed, 10 insertions, 2 deletions

diff --git a/Documentation/public-inbox-v1-format.pod b/Documentation/public-inbox-v1-format.pod
index 3b0e70e1..c960913d 100644
--- a/Documentation/public-inbox-v1-format.pod
+++ b/Documentation/public-inbox-v1-format.pod
@@ -104,6 +104,10 @@ SQLite3 database maintaining a stable mapping of Message-IDs to NNTP
 article numbers.  Used by L<public-inbox-nntpd(1)> and created
 and updated by L<public-inbox-index(1)>.
 
+Users of the L<PublicInbox::WWW> interface will find it
+useful for attempting recovery from copy-paste truncations of
+URLs containing long Message-IDs.
+
 Automatically updated by L<public-inbox-mda(1)>,
 L<public-inbox-learn(1)> and L<public-inbox-watch(1)>.
 
@@ -135,8 +139,12 @@ the "overview" DB also exists in the xapian directory for v1
 repositories.  See L<public-inbox-v2-format(5)/OVERVIEW DB>
 
 Our use of the L</OVERVIEW DB> requires Xapian document IDs to
-remain stable.  Thus, use of L<xapian-compact(1)> and
-L<copydatabase(8)> require the use of C<--no-renumber> switch.
+remain stable.  Using L<public-inbox-compact(1)> and
+L<public-inbox-xcpdb(1)> wrappers are recommended over tools
+provided by Xapian.
+
+This directory is large, often two to three times the size of
+the objects stored in a packed git repository.
 
 =item $GIT_DIR/ssoma.index