Spped up MySQL query - mysql

Question

I need help speeding up a MySQL query that's running extremely slowly. It's taking over 35 seconds to return 900 rows.
Does anyone have ideas how I can speed things up on this query?
Many thanks in advance
select products.*,
p.price as lowest_price,
products_images.thumbnail
from products
inner join products_categories on products_categories.product_id = products.id
inner join products_colours on products_colours.product_id = products.id
inner join products_quantity_pricing on products_quantity_pricing.product_id = products.id
left join ( select min(price) as price, product_id from products_quantity_pricing group by products_quantity_pricing.product_id ) as p on p.product_id = products.id
inner join products_images on products_images.product_id = products.id
where products.id > 0 group by products.id
order by products.product_name
Here is the setup of the tables involved:
CREATE TABLE IF NOT EXISTS `products_categories` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`product_id` smallint(5) unsigned zerofill NOT NULL,
`category` int(11) NOT NULL,
`sub_category` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1016 ;
CREATE TABLE IF NOT EXISTS `products` (
`product_prefix` varchar(10) NOT NULL,
`id` smallint(5) unsigned zerofill NOT NULL AUTO_INCREMENT,
`supplier_id` int(11) NOT NULL,
`product_code` varchar(50) NOT NULL,
`supplier_product_code` mediumtext NOT NULL,
`product_name` varchar(200) NOT NULL,
`product_description` text NOT NULL,
`print_area` varchar(100) DEFAULT NULL,
`print_position` varchar(100) DEFAULT NULL,
`dimensions` varchar(100) DEFAULT NULL,
`origination` tinytext,
`unit_cost` decimal(9,2) NOT NULL,
`updated` datetime NOT NULL,
`url` varchar(255) NOT NULL,
PRIMARY KEY (`id`),
KEY `product_code` (`product_code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=901 ;
CREATE TABLE IF NOT EXISTS `products_images` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`product_id` smallint(5) unsigned zerofill NOT NULL,
`fullsize` varchar(255) NOT NULL,
`midsize` varchar(255) NOT NULL,
`thumbnail` varchar(255) NOT NULL,
`updated` datetime NOT NULL,
`colour_tag` varchar(100) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=2402 ;
CREATE TABLE IF NOT EXISTS `products_colours` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`product_id` smallint(5) unsigned zerofill NOT NULL,
`colour` varchar(100) NOT NULL,
PRIMARY KEY (`id`),
KEY `product_id` (`product_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=2546 ;
CREATE TABLE IF NOT EXISTS `products_quantity_pricing` (
`product_id` smallint(5) unsigned zerofill NOT NULL,
`quantity` smallint(6) NOT NULL,
`price` decimal(9,2) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

Answer 1

Add indexes on the product_id columns in all the tables.
In the products_quantity_pricing, a composite index on (product_id, price) will also speed up finding the minimum price for each product. If you create this composite index, you don't need to create a separate index just on product_id; the prefix of a composite index also serves as an index of its own.