sorry 以后多给点分
已经解决前2道3) Any performance issue of that “SELECT” statement if there are more than 10 million rows of data in the client table? create table client (
ID int not null identity(1,1),
Gender char(1) not null check (Gender in ('F','M')),
Age tinyint not null
)
alter table client
add constraint PK_client_ID primary key (ID, Gender)
go
select ID, Age from client with (nolock) where Gender = 'F'
go
据说可以用到索引???(如何解释)
已经解决前2道3) Any performance issue of that “SELECT” statement if there are more than 10 million rows of data in the client table? create table client (
ID int not null identity(1,1),
Gender char(1) not null check (Gender in ('F','M')),
Age tinyint not null
)
alter table client
add constraint PK_client_ID primary key (ID, Gender)
go
select ID, Age from client with (nolock) where Gender = 'F'
go
据说可以用到索引???(如何解释)
解决方案 »
免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货