固破的专栏

http://imysql.cn/node/89Descending indexing and loose index scan降序索引和减轻索引扫描Comments to my previous posts, especially this one by Gokhan inspired me to write a bit about descending indexes and about lo...

update a inner join b on a.bid=b.id set a.x=b.x,a.y=b.y ;