xcpdb: use DB_DANGEROUS for temporary Xapian DBs

New Xapian database shards are ideal candidates for the
DB_DANGEROUS flag since these shards aren't visible to
reader processes while they're being written to.

diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index 1f5826990ac0e34a2993d1c4e9b4b36aafd9a579..2cc48c8e2d2453444b6efb1d09f85320b9d0f5c2 100644 (file)
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -472,6 +472,7 @@ sub xapian_write_prep ($) {
        my $flag = eval($PublicInbox::Search::Xap.'::DB_CREATE()');
        die if $@;
        $flag |= $PublicInbox::SearchIdx::DB_NO_SYNC if !$opt->{fsync};
+       $flag |= $PublicInbox::SearchIdx::DB_DANGEROUS;
        (\%PublicInbox::Search::X, $flag);
 }