The file holds one record per line, with fields joined by
separator (a tab by default).
<?php
$db = new Pdo\Pgsql('pgsql:dbname=test host=localhost', $user, $pass);
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->exec('CREATE TABLE fruits (id int, name text, qty int)');
file_put_contents('/tmp/fruits.tsv', "1\tapple\t10\n2\tbanana\t20\n");
$db->copyFromFile('fruits', '/tmp/fruits.tsv');
echo $db->query('SELECT count(*) FROM fruits')->fetchColumn(), "\n";
?>
The above example will output: