msgmap: use TRUNCATE for journal_mode, for now

[public-inbox.git] / lib / PublicInbox / Msgmap.pm

diff --git a/lib/PublicInbox/Msgmap.pm b/lib/PublicInbox/Msgmap.pm
index 5a89b85a51e297660291f0c4e5477bd2865608da..5fe14383ac484a79e1b279b718e28db68b5449d4 100644 (file)
--- a/lib/PublicInbox/Msgmap.pm
+++ b/lib/PublicInbox/Msgmap.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2015-2018 all contributors <meta@public-inbox.org>
+# Copyright (C) 2015-2020 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # bidirectional Message-ID <-> Article Number mapping for the NNTP
@@ -48,6 +48,10 @@ sub new_file {
 
        if ($writable) {
                create_tables($dbh);
+
+               # TRUNCATE reduces I/O compared to the default (DELETE)
+               $dbh->do('PRAGMA journal_mode = TRUNCATE');
+
                $dbh->begin_work;
                $self->created_at(time) unless $self->created_at;
 
@@ -211,11 +215,12 @@ ORDER BY num ASC LIMIT 1000
 }
 
 sub msg_range {
-       my ($self, $beg, $end) = @_;
+       my ($self, $beg, $end, $cols) = @_;
+       $cols //= 'num,mid';
        my $dbh = $self->{dbh};
        my $attr = { Columns => [] };
-       my $mids = $dbh->selectall_arrayref(<<'', $attr, $$beg, $end);
-SELECT num,mid FROM msgmap WHERE num >= ? AND num <= ?
+       my $mids = $dbh->selectall_arrayref(<<"", $attr, $$beg, $end);
+SELECT $cols FROM msgmap WHERE num >= ? AND num <= ?
 ORDER BY num ASC LIMIT 1000
 
        $$beg = $mids->[-1]->[0] + 1 if @$mids;