SQL 子查询还是 INNER-JOIN？

我有以下两个疑问：

declare @UserId as int
set @UserId = 1

-- Query #1: Sub-query
SELECT
    u.[Id] ,
    u.[Name] ,
    u.[OrgId] AS Organization,
    (SELECT o.[Name] FROM Org o WHERE o.Id = u.OrgId) As OrganizationName,
    [UserRoleId] AS UserRole,
    [UserCode] AS UserCode,
    [EmailAddress] As EmailAddress, 
    (SELECT SearchExpression FROM SearchCriteria WHERE UserId = @UserId AND IsDefault=1 ) AS SearchCriteria,
    (SELECT PageSize FROM UserPreferences WHERE UserId = @UserId) AS UserPreferencePageSize,
    (SELECT DrilldownPageSize FROM UserPreferences WHERE UserId = @UserId) AS UserPreferenceDrilldownPageSize
    FROM [User] as u
WHERE u.Id = @UserId

-- Query #2: LEFT OUTER JOIN-query
SELECT
    u.[Id] ,
    u.[Name] ,
    u.[OrgId] AS Organization,
    (SELECT o.[Name] FROM Org o WHERE o.Id = u.OrgId) As OrganizationName,
    [UserRoleId] AS UserRole,
    [UserCode] AS UserCode,
    [EmailAddress] As EmailAddress, 
    sc.SearchExpression As SearchExpression,
    up.PageSize As PageSize,
    up.DrilldownPageSize As DrilldownPageSize    
    FROM [User] as u
LEFT OUTER JOIN [UserPreferences] as up ON u.id = up.UserId
LEFT OUTER JOIN [SearchCriteria] as sc ON u.id = sc.UserId
    WHERE ISNULL(sc.IsDefault,1)=1 AND u.Id = @UserId

查询执行计划统计：（相对于批次的查询成本）

• 查询#1（子查询）：56%
• 查询#2（连接）：44%

我认为子查询是最佳的，因为子查询将在应用 WHERE 过滤器后执行。统计数据表明 Query#2 - JOIN 方法更好。

请建议。另外，作为一个中等的 SQL-Server 用户，我怎样才能得出哪个查询更好（除了执行计划之外的任何查询，如果它更有帮助的话）

谢谢。

连接比子查询更快。

子查询导致繁忙的磁盘访问，想想硬盘的读写针（头？）当它访问时会来回：User、SearchExpression、PageSize、DrilldownPageSize、User、SearchExpression、PageSize、DrilldownPageSize、User...等等。

加入作品集中精力对前两个表结果的操作，任何后续连接都将集中连接第一个连接表的内存中（或缓存到磁盘）结果，依此类推。读写针移动更少，因此速度更快