use DBI;

$dad = DBI->connect('dbi:Pg:', '', '', {AutoCommit => 0, RaiseError => 1});
$kid = DBI->connect('dbi:Pg:', '', '', {AutoCommit => 0, RaiseError => 1});

$dad->do("SET bytea_output = 'escape'");
$dad->do('CREATE TEMP TABLE x ()'); # Get an xid
($snap) = $dad->selectrow_array('SELECT pg_export_snapshot()');

$kid->do("SELECT pg_import_snapshot('$snap')");