What strategies can be used to optimize the structure of a database table for better functionality in PHP applications?

To optimize the structure of a database table for better functionality in PHP applications, you can consider the following strategies: 1. Normalize your database tables to reduce redundancy and improve data integrity. 2. Index frequently queried columns to speed up data retrieval. 3. Use appropriate data types for columns to minimize storage space and improve query performance.

// Example of creating a normalized table with indexes in MySQL using PHP
$sql = "CREATE TABLE users (
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(30) NOT NULL,
    email VARCHAR(50) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    INDEX(username),
    INDEX(email)
)";