How can the use of "SELECT *" in a query impact performance and efficiency in PHP MySQL?

Using "SELECT *" in a query can impact performance and efficiency in PHP MySQL because it retrieves all columns from a table, even if not all columns are needed. This can lead to unnecessary data being fetched and transferred, resulting in slower query execution times. To improve performance, it is recommended to explicitly specify the columns needed in the SELECT statement.

// Specify the columns needed in the SELECT statement instead of using "SELECT *"
$query = "SELECT column1, column2, column3 FROM table_name WHERE condition";
$result = mysqli_query($connection, $query);

// Process the query result
if ($result) {
    while ($row = mysqli_fetch_assoc($result)) {
        // Process each row
    }
}