如果SQL Server只运行了很短的一段时间,你可能不想去使用一些dmv统计数据,因为他们并不是一个能够代表SQL Server实例可能遇到的真实工作负载的样本。另一方面,SQL Server只能维持一定量的信息,有些信息在进行SQL Server性能管理活动的时候可能丢失,所以如果SQL Server已经运行了相当长的一段时间,一些统计数据就有可能已...
ALTERINDEX [索引名]ON[表名] REORGANIZE; 实例: ALTERINDEX [PandaIndex]ON[PandaTable] REORGANIZE; 重新生成索引-使用SSMS# 进入重新生成索引的界面 查看碎片情况,点击确定 重新生成索引-使用T-SQL# ALTERINDEX [索引名]ON[表名] REBUILDWITH(ONLINE=ON) 实例: ALTERINDEX [PandaIndex]ON[PandaTable] REBUILD...
SqlServer.TransactSql.ScriptDom Microsoft.SqlServer.TransactSql.ScriptDom AbortAfterWaitType AcceleratedDatabaseRecoveryDatabaseOption AddAlterFullTextIndexAction AddFileSpec AddMemberAlterRoleAction AddSearchPropertyListAction AddSensitivityClassificationStatement AddSignatureStatement AdHocDataSource AdHocTableReference ...
SQL logins created by using FROM CERTIFICATE, FROM ASYMMETRIC KEY, and FROM SID are supported. See CREATE LOGIN. Server principals (logins) are created at the server level, and users (database principals) are created at the database level. Microsoft Entra logins created with the CREATE LOG...
This takes you to the article DATEPART (Transact-SQL). As another example, to find out how to work with strings, search for string functions. This takes you to the article String Functions (Transact-SQL).What you will learnThis tutorial shows you how to create a database, create a table...
The former doesn't return the outer table's row if the table-valued function returns an empty set for it, while the latter returns a row with NULLs instead of the function's columns. To use the APPLY operator, first create the following Arrays table, which stores arrays of comma-...
sql_variantcan be assigned a default value. This data type can also have NULL as its underlying value, but the NULL values will not have an associated base type. Also,sql_variantcannot have anothersql_variantas its base type. A unique, primary, or foreign key may include columns of typesq...
CREATE XML INDEX index_name ON ( xml_column_name ) USING XML INDEX sxi_index_name FOR ( <xquery_or_sql_values_path> ) [WITH ( <index_options> )] ::= { database_name.schema_name.table_name | schema_name.table_name | table_name } <xquery_or_sql_values_path>::= <path_name...
Metadata information in SQL Server 2008 reports meaningful precision and scale values for the new date and time data types. In thesys.columnsview, theprecisionattribute describes the total number of characters in the default literal string representation of the value, and the scale describes the num...
Use modification statements that convert nulls and include logic that eliminates rows with null values from queries. Be aware that in Transact-SQL, NULL is not an empty or "nothing" value. It is a placeholder for an unknown value and can cause unexpected behavior, especially when qu...