第一种:select * from test_filter_index where col2 = 'A632395' and col3 is null 第二种:select * from test_filter_index where col2 = 'A632395' and col3 is not null 如果走了filter索引,也即idx_col2 ,查询出来的结果可能就是不完整的,因此不会使用到idx_col2 这个索引 事实上,执行计划很...
This article describes how to create a filtered index using SQL Server Management Studio (SSMS) or Transact-SQL. A filtered index is an optimized disk-based rowstore nonclustered index especially suited to cover queries that select from a well-defined subset of data. It uses a filter predicate...
This article describes how to create a filtered index using SQL Server Management Studio (SSMS) or Transact-SQL. A filtered index is an optimized disk-based rowstore nonclustered index especially suited to cover queries that select from a well-defined subset of data. It uses a filter predicate...
Msg10609,Level16, State1, Line9Filteredindex'IX_FactTable1_COMPCOL_FOR_INDEX_COL3'cannot be createdontable'dbo.FactTable'because thecolumn'COMPCOL_FOR_INDEX_COL3'inthe filter expressionisa computedcolumn. Rewrite the filter expression so that it doesnotinclude thiscolumn. 原来SQL SERVER 不允许对...
This article describes how to create a filtered index using SQL Server Management Studio (SSMS) or Transact-SQL. A filtered index is an optimized disk-based rowstore nonclustered index especially suited to cover queries that select from a well-defined subset of data. It uses a filter predicate...
This article describes how to create a filtered index using SQL Server Management Studio (SSMS) or Transact-SQL. A filtered index is an optimized disk-based rowstore nonclustered index especially suited to cover queries that select from a well-defined subset of data. It uses a filter predicate...
This article describes how to create a filtered index using SQL Server Management Studio (SSMS) or Transact-SQL. A filtered index is an optimized disk-based rowstore nonclustered index especially suited to cover queries that select from a well-defined subset of data. It uses a filter predicate...
指定NOEXPAND並透過選擇性的INDEX()子句,強制查詢優化器使用指定的索引。 NOEXPAND 只能指定給索引檢視表,且不得指定給尚未編製索引的檢視表。 僅在特定版本的 SQL Server 中,查詢優化器才支援自動使用索引檢視表。 Azure SQL 資料庫和 Azure SQL 受控執行個體支援在不指定 NOEXPAND 提示的情況下自動使用索引檢視表。
SQL Server-聚焦过滤索引提高查询性能 过滤索引,在查询条件上创建非聚集索引 过滤索引是SQL 2008的新特性,被应用在表中的部分行,所以利用过滤索引能够提高查询,相对于全表扫描它能减少索引维护和索引存储的成本。当我们在索引上应用WHERE条件时就是过滤索引。也就是满足如下格式:...
create unique index production.nullidx on production.product(code) where production.product(code) is not null So the filter takes out the nulls. Apparently this is also really useful if you are migrating your database from another provider to SQL Server. ...