SQL Server提供了一个系统功能DBCC FREEPROCCACHE去清理执行计划缓存,参数是上文提到的具体的执行计划句柄(plan_handle),不加参数就全清了,注意一下即可。 --Remove the specific plan from the cache.清除特定的执行计划DBCCFREEPROCCACHE (0x060006001ECA270EC0215D05000000000000000000000000);GO 对于DBCC FREEPROCCACHE去...
As an application, SQL Server may request system resources as it executes a query andwaitsfor its request to be completed. These waits are represented by SQL Server wait statistics. SQL Server tracks wait information any time that a user connection or session_id is waiting. This wait informatio...
The SQL Server Query Optimizer doesn't choose only the execution plan with the lowest resource cost; it chooses the plan that returns results to the user with a reasonable cost in resources and that returns the results the fastest. For example, processing...
The SQL Server Query Optimizer doesn't choose only the execution plan with the lowest resource cost; it chooses the plan that returns results to the user with a reasonable cost in resources and that returns the results the fastest. For example, processing a query in parallel typically uses ...
若要执行sys.dm_exec_text_query_plan,用户必须是 sysadmin固定服务器角色的成员,或者对服务器具有 VIEW SERVER STATE 权限。 SQL Server 2022 及更高版本的权限 要求对服务器具有 VIEW SERVER PERFORMANCE STATE 权限。 示例 A. 检索运行速度缓慢的 Transact-SQL 查询或批处理的缓存查询计划 ...
Execution plans for any specific query in SQL Server typically evolve over time due to a number of different reasons such as statistics changes, schema changes, creation/deletion of indexes, etc. The procedure cache (where cached query plans are stored) only stores the latest execution plan. Pl...
33ExceptionIndicates that an exception has occurred in SQL Server. 34SP:CacheMissIndicates when a stored procedure isn't found in the procedure cache. 35SP:CacheInsertIndicates when an item is inserted into the procedure cache. 36SP:CacheRemoveIndicates when an item is removed from the procedure...
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Chapter 1. SQL Server Setup and Configuration Database servers never live in a vacuum. They belong to an ecosystem of one or more applications used by customers. Application databases are … - Selection from SQL Server Advanced Troubleshooting and Perfo
USEAdventureWorks2022; GOSELECT*FROMPerson.Address; GOSELECTplan_handle, st.textFROMsys.dm_exec_cached_plansCROSSAPPLYsys.dm_exec_sql_text(plan_handle)ASstWHEREtextLIKEN'SELECT * FROM Person.Address%'; GO 结果集如下。 输出 SQL -- Remove the specific plan from the cache.DBCC FREEPROCCACHE (0x...