In what situations should developers consider optimizing PHP scripts to prevent performance issues related to server requests?

Developers should consider optimizing PHP scripts when they notice slow server response times or high server resource usage. This can be caused by inefficient code, excessive database queries, or large file operations. Optimizing PHP scripts can involve techniques such as caching, minimizing database queries, using efficient algorithms, and optimizing loops.

// Example of optimizing PHP script by caching database query results
$cache_key = 'posts_cache';
$posts = get_transient($cache_key);

if (false === $posts) {
    $posts = get_posts(array('post_type' => 'post'));
    set_transient($cache_key, $posts, 3600); // Cache for 1 hour
}

foreach ($posts as $post) {
    // Display post content
}