index+xcpdb: support --no-sync flag

This allows us to speed up indexing operations to SQLite
and Xapian.

Unfortunately, it doesn't affect operations using
`xapian-compact' and the compactor API, since that doesn't seem
to support Xapian::DB_NO_SYNC, yet.

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/PublicInbox/Over.pm b/lib/PublicInbox/Over.pm
index e3f26456..f32743c0 100644
--- a/lib/PublicInbox/Over.pm
+++ b/lib/PublicInbox/Over.pm
@@ -40,6 +40,7 @@ sub dbh_new {
                 $st = pack('dd', $st[0], $st[1]);
         } while ($st ne $self->{st} && $tries++ < 3);
         warn "W: $f: .st_dev, .st_ino unstable\n" if $st ne $self->{st};
+        $dbh->do('PRAGMA synchronous = OFF') if ($rw // 0) > 1;
         $dbh;
 }