How does the server-client connection impact the overall performance of a PHP application compared to SQL query execution time?

The server-client connection can impact the overall performance of a PHP application by introducing latency and overhead in communication between the server and client. This can slow down the execution of SQL queries and other operations, affecting the overall performance of the application. To improve performance, it's important to optimize the server-client connection and minimize unnecessary data transfer.

// Example code to optimize server-client connection by using persistent connections in PHP
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);

// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// Perform SQL queries or operations here

// Close connection
mysqli_close($conn);