貌似上面一种情况是针对oracle优化器的,sql server优化器还没那么智能可以识别出这种参数探嗅的模式,只能对语句一模一样的SQL进行软解析。这里有特殊,除非是明显不会影响查询计划的参数化,比如用主键来做等于限制,无论怎么样都是做cluster index seek,所以SQL SERVER优化器就自动参数化了。 select * from dbo.dimst...
Backing Up and Restoring Databases in SQL Server Backup Overview (SQL Server) Backup Under the Simple Recovery Model Backup Under the Full Recovery Model Backup Under the Bulk-Logged Recovery Model Introduction to Backup and Restore Strategies in SQL Server Creating Full and Differential Backups of ...
SQL Server is Movin' On Up! At last week's WinHEC in Los Angeles, SQL GM Quentin Clark joined Windows Server VP Bill Laing on... Date: 11/10/2008 TPC-E – Raising the Bar in OLTP Performance Glenn Paulley, Director of Engineering at Sybase iAnywhere, posted a commentary titled “The...
In the context of data warehousing, the main objective is to make sure the query optimizer considers the compelling alternatives of access paths for the execution plan of the star join query. SQL Server includes various functionalities in its query optimizer to automatically provide well-performing ...
By using metadata, the columnstore index is able to skip reading in the rowgroups that don't contain data required for the query result, all without actual I/O. 這項功能稱為列群消除,能夠減少全表掃描的 I/O,因而改善查詢效能。 資料行存放區索引何時需要執行完整資料表掃描? 從...
Every layer of the stack affects performance; storage, virtualisation, database and application. Learn more about how Pure, VMware and SQL Server can be tuned to make your application run faster. Learn About SQL Server High Availability
In a multi-site hierarchy, Configuration Manager uses SQL Server replication to transfer data between sites. For more information, see Database replication.Use the following diagram to start troubleshooting SQL Server performance that can impact replication status:...
Report data in SSRS SQL Server mobile reports Reporting Services Security and Protection Report subscriptions Reporting Services tools Extensions URL Access Relational Databases WMI Provider library reference Troubleshoot Reporting Services Developer Technical Reference ...
Where possible, avoid doing loads of string concatenation as it is not a fast process in SQL Server. Have you checked the order of WHERE clauses when using AND? If you have a WHERE clause that includes expressions connected by two or more AND operators, SQL Server will evaluate them from...
When you create and then run a SQL Server trace in Microsoft SQL Server 2012, you experience poor performance in SQL Server 2012. Cause The issue occurs because the Sp_TraceGetdata stored procedure consumes excessive memory resources when you run the trace. Therefore, the siz...