sub runSomeQueries
{
	my $query = "select LocationID, LocationName from Location";
	my $sth = $dbh->prepare($query);
	if ( $sth->execute() )
	{
		while (my $data = $sth->fetchrow_hashref )
		{
			runSomeSubQueries($$data{LocationID});
		}
	}
}


sub runSomeSubQueries
{
	my $locationID = shift;
	my $query = "Delete from Location where LocationID = ?";
	my $sth = $dbh->prepare($query);
	$sth->execute($locationID);
}


##</code><code>##

my $dbh_primary = DBI->connect(XXXX);
my $dbh_backup = DBI->connect(YYYY);
runSomeQueries($dbh_primary);
runSomeQueries($dbh_backup);

##</code><code>##

my $dbh = DBI->connect(XXXX);
my $dbh_tx = DBI->connect(XXXX, AutoCommit => 0);

#  non-transactioned
runSomeQueries($dbh);
runSomeSubQueries($dbh);

#  if you need to transaction a bunch of queries together
runSomeQueries($dbh_tx);
runSomeSubQueries($dbh_tx);
if ( $OK )
{
    $dbh->commit();
}
else
{
    $dbh->rollback();
}