… rules you would learn about MySQL Performance Optimization is to avoid using functions when comparing constants or order by. Ie use indexed_col=N… you look only at ORDER BY clause you would see first query which sorts by function is able to avoid order by while second which… this case MySQL Optimizer is rather smart and is able to do this even if we have function in ORDER BY and exactly…

… with MySQL Optimizer I frequently run into is making poor decision when it comes to choosing between using index for ORDER BY or… there are also bunch of fields which sorting can be performed on such as seller, price, date added etc. Such configuration… * from goods where cat_id=5 and seller_id=1 order by price desc limit 10 \G *************************** 1. row *************************** id: 1 select…