Im having the same issue very slow response time 6 to 7 seconds server overloading. Is there anyway to optimise this query to be less resource intensive. Its in classes/Product.php My host says its a query overloading the database:
"SELECT p.*, product_shop.*, stock.out_of_stock, IFNULL(stock.quantity, 0) as quantity, pl.`description`, pl.`description_short`, MAX(product_attribute_shop.id_product_attribute) id_product_attribute,
pl.`link_rewrite`, pl.`meta_description`, pl.`meta_keywords`, pl.`meta_title`,
pl.`name`, MAX(image_shop.`id_image`) id_image, il.`legend`, m.`name` AS manufacturer_name,
DATEDIFF(
p.`date_add`,
DATE_SUB(
NOW(),
INTERVAL '.(Validate::isUnsignedInt(Configuration::get('PS_NB_DAYS_NEW_PRODUCT')) ? Configuration::get('PS_NB_DAYS_NEW_PRODUCT') : 20).' DAY
)
) > 0 AS new
FROM `'._DB_PREFIX_.'product` p
'.Shop::addSqlAssociation('product', 'p').'
LEFT JOIN '._DB_PREFIX_.'product_attribute pa ON (pa.id_product = p.id_product)
'.Shop::addSqlAssociation('product_attribute', 'pa', false, 'product_attribute_shop.default_on=1').'
'.Product::sqlStock('p', 0, false, $context->shop).'
LEFT JOIN `'._DB_PREFIX_.'product_lang` pl ON (
p.`id_product` = pl.`id_product`
AND pl.`id_lang` = '.(int)$id_lang.Shop::addSqlRestrictionOnLang('pl').'
)
LEFT JOIN `'._DB_PREFIX_.'image` i ON (i.`id_product` = p.`id_product`)'.
Shop::addSqlAssociation('image', 'i', false, 'image_shop.cover=1').'
LEFT JOIN `'._DB_PREFIX_.'image_lang` il ON (i.`id_image` = il.`id_image` AND il.`id_lang` = '.(int)$id_lang.')
LEFT JOIN `'._DB_PREFIX_.'manufacturer` m ON (m.`id_manufacturer` = p.`id_manufacturer`)
WHERE product_shop.`active` = 1
AND product_shop.`show_price` = 1
'.($front ? ' AND p.`visibility` IN ("both", "catalog")' : '').'
'.((!$beginning && !$ending) ? ' AND p.`id_product` IN ('.((is_array($tab_id_product) && count($tab_id_product)) ? implode(', ', $tab_id_product) : 0).')' : '').'
AND p.`id_product` IN (
SELECT cp.`id_product`
FROM `'._DB_PREFIX_.'category_group` cg
LEFT JOIN `'._DB_PREFIX_.'category_product` cp ON (cp.`id_category` = cg.`id_category`)
WHERE cg.`id_group` '.$sql_groups.'
)
GROUP BY product_shop.id_product
ORDER BY '.(isset($order_by_prefix) ? pSQL($order_by_prefix).'.' : '').pSQL($order_by).' '.pSQL($order_way).'
LIMIT '.(int)($page_number * $nb_products).', '.(int)$nb_products;"