**Reported in Launchpad by Baron Schwartz last update 11-10-2012 21:36:00

To help analyze information on which deadlocks are most frequent, pt-deadlock-logger should store a checksum of the query's fingerprint with the record it inserts. A quick and dirty hack in my local copy: add a couple of modules, then:

+# ###########################################################################

1. This is a combination of modules and programs in one – a runnable module.

2. http://www.perl.com/pub/a/2006/07/13/lightning-articles.html?page=last

3. Or, look it up in the Camel book on pages 642 and 643 in the 3rd edition.
   @@ -2371,6 +3515,7 @@
   use English qw(-no_match_vars);
   use List::Util qw(max);
   use Socket qw(inet_aton);
   +Transformers->import(qw(make_checksum));
   use sigtrap qw(handler finish untrapped normal-signals);

use constant PTDEBUG => $ENV{PTDEBUG} || 0;

@@ -2392,6 +3537,8 @@
my $n = qr/(

+)/; # MySQL object name
my $w = qr/(\w+)/; # Words
my $s = qr/(\d{6} .\d:\d\d:\d\d)/; # InnoDB timestamp
+my $qp = new QueryParser();
+my $qr = new QueryRewriter(QueryParser=>$qp);

1. A thread's proc_info can be at least 98 different things I've found in the

2. source. Fortunately, most of them begin with a gerunded verb. These are
   @@ -2489,7 +3636,7 @@
   }

my @cols = qw( server ts thread txn_id txn_time user hostname ip db tbl idx

• lock_type lock_mode wait_hold victim query );
  + lock_type lock_mode wait_hold victim query checksum );
  if ( $o->got('columns') ) {
  @cols = grep { $o->get('columns')->{$_} } @cols;
  }
  @@ -2551,6 +3698,7 @@
  if ( $ins_sth ) {
  foreach my $txn (sort { $a->{thread} <=> $b->{thread} } values %txns) {
  die $text unless $txn->{db};
  + $txn->{checksum} = make_checksum($qr->fingerprint($txn->{query} || ''));
  $ins_sth->execute(@{$txn}{@cols});
  }
  $dest_dbh->commit();
  @@ -3108,6 +4256,7 @@
  wait_hold char(1) NOT NULL,
  victim tinyint unsigned NOT NULL,
  query text NOT NULL,
  + checksum char(32) NOT NULL,
  PRIMARY KEY (server,ts,thread)
  ) ENGINE=InnoDB