Hello, I have two tables: CREATE TABLE categories ( CategoryNumber int(11) NOT NULL, ItemNumber int(11) NOT NULL, KEY CategoryNumber (CategoryNumber), KEY ItemNumber (ItemNumber) ); CREATE TABLE items ( ItemNumber int(11) NOT NULL auto_increment, Description varchar(100) NOT NULL, Price bigint(20) unsigned NOT NULL, KEY Price (Price) ); Each item can have multiple categories. Each table contains more than 1 million records. This kind of query gets executed a lot: SELECT I.* FROM items AS I, categories AS C WHERE C.CategoryNumber = 123 AND C.ItemNumber = I.ItemNumber AND I.Price >= 1000 LIMIT 0,51; I would like to improve the performance of this query. My question is: Would a double index on both fields in the categories table increase performance? In other words, would this structure be better: CREATE TABLE categories ( CategoryNumber int(11) NOT NULL, ItemNumber int(11) NOT NULL, KEY CategoryItem (CategoryNumber,ItemNumber) ); Thanks! Tim --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php