Database error, can't figure out what's causing this

[Halo2Forum.com]

Database error in vBulletin 3.8.1:

Invalid SQL:

SELECT COUNT(DISTINCT userid) AS total
FROM _webblog WHERE state = 'visible';

MySQL Error : Out of memory (Needed 262143972 bytes)
Error Number : 5
Request Date : Friday, February 26th 2010 @ 09:56:21 PM
Error Date : Friday, February 26th 2010 @ 09:56:21 PM
Script : http://www.1800webmasters.com/webmaster/blog_tag.php
Referrer :
IP Address : 203.177.74.139
Username : Unregistered
Classname : vB_Database
MySQL Version :

[Trevor Hannant]

"MySQL Error : Out of memory (Needed 262143972 bytes)"

You need to speak to your host regarding this...

[Halo2Forum.com]

"MySQL Error : Out of memory (Needed 262143972 bytes)"

You need to speak to your host regarding this...

what memory setting controls that specific memory limit?