PHP

Check these

• Don't fetch 10,000 rows and only use 5, use a LIMIT clause

• Make sure you have keys on the right columns

• --log-slow-queries[=file_name] can help here

• So can --log-long-format to show non-indexed queries

• Use mysqldumpslow to look at these

A non-indexed query


<?
mysql_connect('localhost');
mysql_select_db('foo');
$result=mysql_query(
        "select * from users where ts>0");
?>

And an indexed query


<?
  $result = mysql_query(
    "select * from users where id='rasmus'");
  echo "<pre>";
  system('mysqldumpslow');
  echo "</pre>\n";
?>

Output

"; system('mysqldumpslow'); echo "\n"; ?>