the it-madness

Das sieht doch gleich viel besser aus (ca 1M Einträge in der Datenbank):

SELECT sender_ip FROM archive ORDER BY RAND(20090301) LIMIT 10;
-> 10 rows in set (10.00 sec)
-> 10 rows in set (10.54 sec)

SELECT sender_ip FROM ( SELECT  @cnt := COUNT(*) + 1, @lim := 10 FROM archive ) vars STRAIGHT_JOIN ( SELECT  r.*, @lim := @lim – 1 FROM archive r WHERE (@cnt := @cnt – 1) AND RAND(20090301) < @lim / @cnt ) i;
-> 10 rows in set (2.84 sec)
-> 10 rows in set (2.77 sec)