What are some best practices for efficiently storing and retrieving cookie data in PHP, especially when dealing with a large number of entries?

When dealing with a large number of cookie entries in PHP, it is important to efficiently store and retrieve the data to prevent performance issues. One best practice is to serialize the data before storing it in a cookie and unserialize it when retrieving. This helps reduce the size of the data being stored and improves efficiency.

// Serialize the data before storing in a cookie
$data = ['key1' => 'value1', 'key2' => 'value2'];
$serializedData = serialize($data);
setcookie('my_cookie', $serializedData, time() + 3600);

// Unserialize the data when retrieving from the cookie
if(isset($_COOKIE['my_cookie'])) {
    $unserializedData = unserialize($_COOKIE['my_cookie']);
    print_r($unserializedData);
}