Distributed4：SQL Server 分布式数据库性能测试

CREATE TABLE [dbo].[Commits]
(
    [CommitID] [bigint] IDENTITY(1,1) NOT FOR REPLICATION NOT NULL,
    [AuthorID] [bigint] NOT NULL,
    [CreatedDate] [datetime2](7) NOT NULL,
    [CreatedDateKey] [int] NOT NULL,
 CONSTRAINT [PK__Commits_CommitID] PRIMARY KEY CLUSTERED 
(
    [CommitID] ASC,
    [CreatedDateKey] ASC
)
) 

CREATE view [dbo].[view_commits]
as

select [CommitID]
      ,[AuthorID]
      ,[CreatedDate]
      ,[CreatedDateKey]
from dbo.commits c with(nolock)
where c.[CreatedDateKey] between 20150900 and 20160000

union ALL
select [CommitID]
      ,[AuthorID]
      ,[CreatedDate]
      ,[CreatedDateKey]
from db3.tdw.dbo.commits c with(nolock)
where c.[CreatedDateKey] between 20150000 and 20150500

union ALL
select [CommitID]
      ,[AuthorID]
      ,[CreatedDate]
      ,[CreatedDateKey]
from db2.tdw.dbo.commits c with(nolock)
where c.[CreatedDateKey] between 20150500 and 20150900
WITH check OPTION;
GO

select sum(t.cnt) as cnt
from
(
    select count(0) as cnt
    from dbo.commits c  with(nolock)
    where day(c.[CreatedDate])=1

    UNION all
    select p.cnt
    from openquery(db2,
    N'select count(0) as cnt
    from dbo.commits c  with(nolock)
    where day(c.[CreatedDate])=1') as p

    UNION all
    select p.cnt
    from openquery(db3,
    N'select count(0) as cnt
    from dbo.commits c  with(nolock)
    where day(c.[CreatedDate])=1') as p
) as t

static void Main(string[] args)
{
    List<Task> tasks = new List<Task>();
    int c1=0, c2=0, c3=0;

    Task t1 = new Task(()=> 
    {
        c1= GetCount("xxx");
    });

    Task t2 = new Task(() =>
    {
        c2=  GetCount("xxx");
    });

    Task t3 = new Task(() =>
    {
        c3= GetCount("xxx");
    });
    tasks.Add(t1);
    tasks.Add(t2);
    tasks.Add(t3);

    Stopwatch sw = new Stopwatch();
    sw.Start(); 
    t1.Start();
    t2.Start();
    t3.Start();

    Task.WaitAll(tasks.ToArray());

    int sum = c1 + c2 + c3;
    sw.Stop();

    Console.Read();
}

static int GetCount(string str)
{
    using (SqlConnection con = new SqlConnection(str))
    {
        con.Open();
        var cmd = con.CreateCommand();
        cmd.CommandText = @" select count(0) as cnt
        from dbo.commits c  with(nolock)
        where day(c.[CreatedDate]) = 1";
        int count = (int)cmd.ExecuteScalar();
        con.Close();
        return count;
    }
}