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。
The first index created on a view must be a unique clustered index. After the unique clustered index has been created, you can create more nonclustered indexes. Creating a unique clustered index on a view improves query performance, because the view is stored in the database in the same ...
The first index created on a view must be a unique clustered index. After the unique clustered index has been created, you can create more nonclustered indexes. Creating a unique clustered index on a view improves query performance, because the view is stored in the database in the same ...
Using Transact-SQL To create a nonclustered index on a table using Transact-SQL InObject Explorer, connect to an instance of Database Engine withAdventureWorks2022installed. You can downloadAdventureWorks2022fromsample databases. On the Standard bar, selectNew Query. ...
Data validation occurs in the same manner, and the query optimizer does not differentiate between a unique index created by a constraint or manually created. However, creating a UNIQUE constraint on the column makes the objective of the index clear. For more information on UNIQUE constraints, see...
Applies to: SQL Server Azure SQL Database Azure SQL Managed InstanceYou can create clustered indexes on tables by using SQL Server Management Studio or Transact-SQL. With few exceptions, every table should have a clustered index. Besides improving query performance, a clustered index can be ...
index that is independent of a constraint. Data validation occurs in the same manner, and the query optimizer does not differentiate between a unique index created by a constraint or manually created. However, creating a UNIQUE constraint on the column makes the objective of the index clear. ...
Starting with SQL Server 2016 (13.x), in Azure SQL Database, and in Azure SQL Managed Instance, you can use a nonclustered index on a columnstore index to improve data warehousing query performance. For more information, see Columnstore indexes - data warehouse. For additional types of indexe...
This will open the table properties window and if we switch over toStoragepage, there’s aData spaceitem which represents the size of the data in the table in megabytes (in this case 2.68 MB) and the first time when we ran the query without the index, SQL Server had to read every row...
1 CREATE UNIQUE INDEX idx_unique_email ON users (email); By identifying the particular columns utilized in filtering, joining, sorting, and text-based search operations and employing the CREATE INDEX statement to generate suitable indexes, you can improve the query performance of your MySQL databas...