Opencart Report Error

General information for the website: we sell computer games
Description of requirements/features: We are getting a error message when we try and run the export feature in open cart

This is the error message

Error: The SELECT would examine more than MAX_JOIN_SIZE rows; check your WHERE and use SET SQL_BIG_SELECTS=1 or SET MAX_JOIN_SIZE=# if the SELECT is okay
Error No: 1104
SELECT p.product_id, pd.name, GROUP_CONCAT( DISTINCT CAST(pc.category_id AS CHAR(11)) SEPARATOR "," ) AS categories, p.sku, p.upc, p.ean, p.jan, p.isbn, p.mpn, p.location, p.quantity, p.model, m.name AS manufacturer, p.image AS image_name, p.shipping, p.price, p.points, p.date_added, p.date_modified, p.date_available, p.weight, wc.unit, p.length, p.width, p.height, p.status, p.tax_class_id, p.viewed, p.sort_order, pd.language_id, ua.keyword, pd.description, pd.meta_description, pd.meta_keyword, pd.tag, p.stock_status_id, mc.unit AS length_unit, p.subtract, p.minimum, GROUP_CONCAT( DISTINCT CAST(pr.related_id AS CHAR(11)) SEPARATOR "," ) AS related FROM `product` p LEFT JOIN `product_description` pd ON p.product_id=pd.product_id AND pd.language_id=1 LEFT JOIN `product_to_category` pc ON p.product_id=pc.product_id LEFT JOIN `url_alias` ua ON ua.query=CONCAT('product_id=',p.product_id) LEFT JOIN `manufacturer` m ON m.manufacturer_id = p.manufacturer_id LEFT JOIN `weight_class_description` wc ON wc.weight_class_id = p.weight_class_id AND wc.language_id=1 LEFT JOIN `length_class_description` mc ON mc.length_class_id=p.length_class_id AND mc.language_id=1 LEFT JOIN `product_related` pr ON pr.product_id=p.product_id GROUP BY p.product_id ORDER BY p.product_id, pc.category_id;
See also 'System > Error Logs' for more details.
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