联合索引使用规则

假设某个表有一个联合索引（c1,c2,c3,c4）一下——只能使用该联合索引的c1,c2,c3部分 A where c1=x and c2=x and c4>x and c3=x B where c1=x and c2=x and c4=x order by c3 C where c1=x and c4= x group by c3,c2 D where c1=? and c5=? order b

>>阅读原文<<