問(wèn)題1:55-60和900-905都是加了5為什么掃描rows不一樣一個(gè)是5一個(gè)6?。。?/h1>

explain SELECT film_id ,description FROM sakila.film WHERE film_id>55 and film_id<=60 ?ORDER BY film_id ?LIMIT 1,5

1 SIMPLE film range PRIMARY,idx_filmid PRIMARY 2 5 Using where

?EXPLAIN SELECT film_id ,description FROM sakila.film WHERE film_id>900 and film_id<=905 ?ORDER BY film_id ?LIMIT 1,5

1 SIMPLE film range PRIMARY,idx_filmid PRIMARY 2 6 Using where

問(wèn)題1:55-60和900-905都是加了5為什么掃描rows不一樣一個(gè)是5一個(gè)6?。。。?？？？？

http://idcbgp.cn/wenda/detail/id/237619?page=2

再就是film_id是主鍵但是：

[SQL]SELECT film_id ,description FROM sakila.film ORDER BY film_id LIMIT 50,5

受影響的行: 0

時(shí)間: 0.001s

1 SIMPLE ?film ?ALL ? 1000 ? Using filesort

掃描Rows 是1000，用到了filesort？？