lei: avoid SQLite COUNT() for dedupe

SQLite COUNT() is a slow operation that does a full table scan
with no conditions.  There's no need for it, since lei dedupe
only needs to know if it's empty or not to decide between
new/ and cur/ for Maildir outputs.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/LeiXSearch.pm b/lib/PublicInbox/LeiXSearch.pm
index cac7fb7d..3414e87d 100644
--- a/lib/PublicInbox/LeiXSearch.pm
+++ b/lib/PublicInbox/LeiXSearch.pm
@@ -504,7 +504,7 @@ sub do_query {
                 my $F_SETPIPE_SZ = $^O eq 'linux' ? 1031 : undef;
                 if ($l2m->{-wq_nr_workers} > 1 &&
                                 $l2m->{base_type} =~ /\A(?:maildir|mbox)\z/) {
-                        # setup two barriers to coordinate dedupe_nr
+                        # setup two barriers to coordinate ->has_entries
                         # between l2m workers
                         pipe(my ($a_r, $a_w)) or die "pipe: $!";
                         fcntl($a_r, $F_SETPIPE_SZ, 4096) if $F_SETPIPE_SZ;