每当SQL服务器需要访问匹配的索引键值的索引项,它开始在根页和工作的方式通过一个页面在索引中的每个水平直到到达叶级页包含索引键进入。在我们的十亿行表的例子,五页的阅读会从根页以SQL Server的叶级页和其所需的进入;在我们为例,三读就够了。在聚集索引叶级别,这项将实际数据行;非聚集索引中,这个条目包含聚...
To find the first page in the chain of data pages, SQL Server follows the leftmost pointers from the root node of the index. This illustration shows the structure of a clustered index in a single partition. See Also Concepts Heap Structures Nonclustered Index Structures Table and Index ...
1. 数据表的基本结构 当建立一个新表时,系统将在磁盘中分配一段以8K为单位的连续空间;当第一个8K用完的时候,SQL Server指针会自动分配8K的空间。每个8K空间成为一个数据页(Page),又称页面或者数据页面,并分配0-7的页号,每个文件的第0页记录引导 信息,叫文件头(File Header);每8个数据页(64K)的组合形成扩...
An index is an on-disk or in-memory structure associated with a table or view that speeds retrieval of rows from the table or view. A rowstore index contains keys built from one or more columns in the table or view. For rowstore indexes, these keys are stored in a tree structure (B+...
An index is an on-disk or in-memory structure associated with a table or view that speeds retrieval of rows from the table or view. A rowstore index contains keys built from one or more columns in the table or view. For rowstore indexes, these keys are stored in a tree structure ...
An index is an on-disk or in-memory structure associated with a table or view that speeds retrieval of rows from the table or view. A rowstore index contains keys built from one or more columns in the table or view. For rowstore indexes, these keys are stored in a tree structure ...
Source Structure Activities Related Content Next steps Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance SQL database in Microsoft Fabric This topic defines the structures that exist during an online index operation and shows the activities associated with these structures. Onlin...
Source Structure Activities Related Content Next steps Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance SQL database in Microsoft Fabric This topic defines the structures that exist during an online index operation and shows the activities associated with these structures. Onlin...
The backward compatible relational index syntax structure will be removed in a future version of SQL Server. Avoid using this syntax structure in new development work, and plan to modify applications that currently use the feature. Use the syntax structure specified in <relational_index_option> inst...
This issue is fixed in the following cumulative update for SQL Server: Cumulative update 6 for SQL Server 2019 Cumulative Update 20 for SQL Server 2017 Note:Depending on index structure and filtered index condition, the SQL Server version canno...