mysqldumpslow是mysql自带的用来分析慢查询的工具
经常使用几个命令
-s ORDER what to sort by (al, at, ar, c, l, r, t), ‘at’ is default
-t NUM just show the top n queries
-g PATTERN grep: only consider stmts that include this string
-r Reverse the sort order
-s，是order的顺序，主要有
c
