[PHP] alternative to ORDER BY RAND() on large tables

[SplitIce]

Never run ORDER BY statements on large tables (e.g 4M tables).

Heres some code that will work as an alternative in most cases.

$resv = mysql_query('SELECT COUNT(*) FROM v3links');
$row = mysql_fetch_row($resv);
$sval = rand(0,$row[0]-15001);
$query=mysql_query("SELECT `id`,`fileid`,`type`, `filename` FROM `v3links` LIMIT ".$sval.",15000");

enjoy.

 

[DEViANCE]

Im guessing this is faster than say:

[COLOR=blue]SELECT * FROM my_table ORDER BY RAND() LIMIT 1;[/COLOR]

??

 

[immortalxx]

rand is very slow, so the more rows u add the slower it gets. rand on php is much faster

 

[hip_hop_x]

$sval = rand(0,$row[0]-15001);
15001 isn't correct, what if you don't have 15001 counts ?

 

[SplitIce]

Lol i said large table i.e 5m rows like me. I got a new version at home