Can't execute query

SELECT model.*, br.name as brend FROM `model` 
					INNER JOIN tiporazmer as tr ON model.id = tr.model_id 
					LEFT JOIN brend as br ON model.brend = br.id 
					WHERE model.`struktura`=197 AND model.`descriptor`!='proxes_sport_2'
					ORDER BY RAND() LIMIT 3
					

MySQL Error: Disk full (/var/tmp/#sql_4a1_1); waiting for someone to free some space...

This script cannot continue, terminating.