slow join

[Oliver Schiessl]

MySQL 3.23.58:
ive got 2 tables with ca. 30000 entrys each
now i wanna join, if one entry is in the one table, which isnt in the  
other one
so this will be a normal join:

Tabelle1:
Artikelnummer, blah, blah, blah

Tabelle2:
Artikelnummer, blah, blah, blah


select Tabelle1.Artikelnummer from Tabelle1 LEFT JOIN Tabelle2 ON  
Tabellle1.Artikelnummer=Tabelle2.Artikelnummer where  
Tabelle2.Artikelnummer is null

now i have the problem that this join on my Xeon 2.4GHz with  
Serial-ATA-disks after 1 1/2 hours isnt ready?!!?

a test with 2 tables with ca. 1000 entries each gave a response after only  
2 seconds.

now... can someone tell me... isnt it faster possible???
i am at least faster with some b*lls**t like...

$query = "select artikelnummer from tabelle1";
while ($row = mysql_fetch_array($result)) {
	$query = "select artikelnummer from tabelle2 where  
artikelnummer='".$row['artikelnummer']."'";
	if (mysql_fetch_array(mysql_query($query))) echo $row['artikelnummer']
}

Oliver