索引主要目的是提高了SQL Server系统的性能,加快数据的查询速度与减少系统的响应时间 。 但是索引对于提高查询性能也不是万能的,也不是建立越多的索引就越好。索引建少了,用 WHERE 子句找数据效率低,不利于查找数据。索引建多了,不利于新增、修改和删除等操作,因为做这些操作时,SQL SERVER 除了要更新数据表本身,还...
索引主要目的是提高了SQL Server系统的性能,加快数据的查询速度与减少系统的响应时间 。 但是索引对于提高查询性能也不是万能的,也不是建立越多的索引就越好。索引建少了,用 WHERE 子句找数据效率低,不利于查找数据。索引建多了,不利于新增、修改和删除等操作,因为做这些操作时,SQL SERVER 除了要更...
For more information, see XML indexes (SQL Server). SQL Server 2012 SP1 introduced a new type of XML index known as a Selective XML Index. This new index can improve querying performance over data stored as XML, allow for faster indexing of large XML data workloads, and improve scala...
如需詳細資訊,請參閱 FILESTREAM (SQL Server)。<object>::=要編製索引的完整或非完整物件。database_name資料庫的名稱。schema_name資料表或檢視所屬之結構描述的名稱。table_or_view_name要建立索引之資料表或檢視的名稱。必須利用 SCHEMABINDING 定義檢視表,才能在該檢視表上建立索引。 必須先在檢視表上建立唯一...
Syntax for SQL Server and Azure SQL Database:syntaxsql Copy -- Create a clustered columnstore index on disk-based table. CREATE CLUSTERED COLUMNSTORE INDEX index_name ON { database_name.schema_name.table_name | schema_name.table_name | table_name } [ ORDER (column [ , ...n ] ) ] ...
Applies to: SQL Server (Starting with SQL Server 2016 (13.x)) and Azure SQL DatabaseCOMPRESS_ALL_ROW_GROUPS provides a way to force OPEN or CLOSED delta rowgroups into the columnstore. With this option, it isn't necessary to rebuild the columnstore index to empty the delta rowgroups. ...
Applies to: SQL Server (Starting with SQL Server 2016 (13.x)) and Azure SQL DatabaseCOMPRESS_ALL_ROW_GROUPS provides a way to force OPEN or CLOSED delta rowgroups into the columnstore. With this option, it isn't necessary to rebuild the columnstore index to empty the delta rowgroups. ...
To see which indexes the query optimizer uses for a specific query, in SQL Server Management Studio, on the Query menu, select Include Actual Execution Plan.Do not always equate index usage with good performance, and good performance with efficient index use. If using an index always helped ...
To see which indexes the query optimizer uses for a specific query, in SQL Server Management Studio, on the Query menu, select Include Actual Execution Plan.Do not always equate index usage with good performance, and good performance with efficient index use. If using an index always helped ...
如需詳細資訊,請參閱 FILESTREAM (SQL Server)。<object>::=要編製索引的完整或非完整物件。database_name資料庫的名稱。schema_name資料表或檢視所屬之結構描述的名稱。table_or_view_name要建立索引之資料表或檢視的名稱。必須利用 SCHEMABINDING 定義檢視表,才能在該檢視表上建立索引。 必須先在檢視表上建立唯一...