Have you been involved in improving the performance and efficiency of SQL queries?

Yes, I have worked on improving the performance of SQL queries in PHP projects. I applied the following approaches:

• Analyzed execution plans using EXPLAIN to identify bottlenecks.
• Optimized indexes by adding or modifying them to speed up queries.
• Rewrote complex queries, breaking them into simpler ones or using JOINs instead of subqueries.
• Cached results of frequently executed queries.
• Used prepared statements to enhance efficiency and security.

An example of an optimized query using PDO:

$stmt = $pdo->prepare('SELECT * FROM users WHERE status = :status');
$stmt->execute(['status' => 'active']);
$activeUsers = $stmt->fetchAll();

These measures significantly improved application speed and reduced database load.