# If RaiseError is false, begin_work() will:
    #     return true if a new transaction was started
    #     return false if already in a transaction
    #     croak if transactions not supported
    #
    my $started_a_new_transaction = 0;
    eval {
        local $dbh->{RaiseError} = 0;
        $started_a_new_transaction = $dbh->begin_work;
    };
    $self->{_can_do_transactions} = $@ ? 0 : 1;
    eval { $dbh->rollback } if $started_a_new_transaction;