在前面的查询中,SQL Server 读取根节点页并检索每个叶节点页和行以进行数据检索。 现在让我们在 SQL Server的EmpContactNumber列上的Employee表上 创建一个唯一的非聚集索引作为索引键: CREATEUNIQUENONCLUSTERED INDEX IX_NonClustered_EmployeeONdbo.Employee(EmpContactNumber); 1 在我们解释这个索引之前,重新运行 SEL...
首先我们一下,在SQL Server 2014 Management Studio中,如何为一张表设置Non-Clustered index 具体可以参考 https://docs.microsoft.com/en-us/sql/relational-databases/indexes/create-unique-indexes 在SQL Server Management Studio中,点击表,右键选择"Design". 然后在菜单栏中选择"Table Designer" => "Indexes/Key...
设在SQL Server 2008中,要在T1表的C1列上建立一个非聚集的唯一索引。请补全下列语句: CRE ATE[8]NONCLUSTERED INDEX idx_t1 ON T1(C1) 相关知识点: 试题来源: 解析 正确答案:UNIQUE 解析:关键字UNIQUE是用来注明该索引是唯一索引,关键字NONCLUSTERED是用来注明该索引是非聚集索引,关键字CLUSTERED是用来注明该...
If the nonclustered index is unique, the data row locator must be accounted for in all rows at the leaf level. If the nonclustered index is over a heap, the data row locator is the heap RID (size 8 bytes). Num_Leaf_Cols=Num_Leaf_Cols+ 1 ...
第1个最简单的方法就是列上定义一个主键（PRIMARYKEY）约束。SQLServer通过在表上创建那列的唯一聚集索引来施行主键（PRIMARYKEY）约束。另外一个方法是通过CREATECLUSTEREDINDEX语句来常见唯一聚集索引——但当你不指定UNIQUE属性时，SQLServer默认是会为你创建非唯一的聚集索引！
This first one has to do with the creation of non-unique clustered indexes...Many of you probably already realize that if you don't explicitly create a unique clustered index in Sql Server, the engine will unique-ify the clustered index for you anyhow, since it's used for pointers ...
SQL Server automatically creates indexes when PRIMARY KEY and UNIQUE constraints are defined on table columns. For example, when you create a table with a UNIQUE constraint, Database Engine automatically creates a nonclustered index. If you configure a PRIMARY KEY, Database Engine automatically ...
After a unique clustered index has been created on a view, nonclustered indexes can be created. For more information, seeCreate indexed views. Security Permissions Requires ALTER permission on the table or view. User must be a member of thesysadminfixed server role or thedb_ddladminanddb_owner...
Rebuilding a non-unique clustered index: Aha! This is different from SQL Server 2000. SQL Server 2005 will RE-USE the old uniquifier values so the cluster keys don't change. This means that non-clustered indexes are NOT rebuilt in this case - that's very cool!...
If you need to do both, particularly if point lookups are frequent, you can consider creating two indexes: it is possible to create both a hash and a nonclustered index with the same index key. Hash indexes require an estimate of the number of unique index...