What are the potential drawbacks of using "DISTINCT" in MySQL queries for PHP applications?

Using "DISTINCT" in MySQL queries can impact performance as it requires the database to scan and remove duplicates from the result set. This can slow down the query execution, especially on large datasets. To optimize the query, consider using other methods such as grouping or filtering the data to achieve the desired results without the need for DISTINCT. 

// Example query without using DISTINCT
$sql = "SELECT column1, column2 FROM table_name GROUP BY column1, column2";
$result = mysqli_query($connection, $sql);

// Process the query result
if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
        // Process each row
    }
}

Keywords

DISTINCT MySQL queries PHP applications performance duplicate rows

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