(2) 单击任务板中的“Create an Index” 链接,出现如图8-3 所示的索引创建向导界面。也可以从“Tools ”菜单中选择“izards” 菜单项,则出现如图5-17 所示的选择SQL Server 向导对话框,再从树型目录中选择“Database”下的“Create Index Wizard”选项,也会出现如图8-3 所示的索引创建向导界面。 (3) 单击...
(2) 单击任务板中的“Create an Index” 链接,出现如图8-3 所示的索引创建向导界面。也可以从“Tools ”菜单中选择“izards” 菜单项,则出现如图5-17 所示的选择SQL Server 向导对话框,再从树型目录中选择“Database”下的“Create Index Wizard”选项,也会出现如图8-3 所示的索引创建向导界面。 (3) 单击...
SQL 复制 CREATE UNIQUE INDEX index1 ON schema1.table1 (column1 DESC, column2 ASC, column3 DESC); 主要方案: 从Azure SQL 数据库和 Azure SQL 托管实例中的 SQL Server 2016(13.x)开始,可以在列存储索引上使用非聚集索引来提高数据仓库查询性能。 有关详细信息,请参阅 列存储索引 - 数据仓库。
Define a primary key in the SQL Server Database Engine by using SQL Server Management Studio or Transact-SQL.
When you create a PRIMARY KEY constraint, a unique clustered index on the column or columns is automatically created if a clustered index on the table does not already exist and you do not specify a unique nonclustered index. The primary key column cannot allow NULL values. When you create ...
Ordered clustered columnstore indexes were introduced in SQL Server 2022 (16.x). For more information, see CREATE COLUMNSTORE INDEX. For ordered columnstore index availability, see Columnstore indexes: Overview. Starting with SQL Server 2016 (13.x), you can create the table as a clustered colu...
An index created as part of the constraint is automatically given the same name as the constraint name. For more information, seePrimary and Foreign Key ConstraintsandUnique constraints and check constraints. Index independent of a constraint
SQL 複製 CREATE TABLE Tbl ( id INT PRIMARY KEY, xmlcol XML ); GO CREATE SELECTIVE XML INDEX sxi_index ON Tbl(xmlcol) FOR( pathab = '/a/b' as XQUERY 'node()', pathabc = '/a/b/c' as XQUERY 'xs:double', pathdtext = '/a/b/d/text()' as XQUERY 'xs:string' MAXLENGTH(...
The limits are 16 columns and 900 bytes for versions before SQL Database and SQL Server 2016 (13.x). Columns that are of the large object (LOB) data types ntext, text, varchar(max), nvarchar(max), varbinary(max), xml, or image can't be specified as key columns for an index. ...
The limits are 16 columns and 900 bytes for versions before SQL Database and SQL Server 2016 (13.x). Columns that are of the large object (LOB) data types ntext, text, varchar(max), nvarchar(max), varbinary(max), xml, or image can't be specified as key columns for an index. ...