Learn the basics of the In-Memory OLTP performance features of SQL Server and Azure SQL Database with quick explanations and core code samples for developers.
However, their impact may be limited if your queries are inefficient because of poor table design that results in too many join operations or in inefficient join operations. Schema design is a key performance factor. It also provides information to the server that may be used to optimize query...
When optimizing your database server, you need to tune the performance of individual queries. This is as important as—perhaps even more important than—tuning other aspects of your server installation, that affect performance, such as hardware and software configurations....
As part of supportability improvement, SQL Server 2012 Service Pack 2 made an improvement. This improvement will help in situations where you have large number of rows inserted into a table variable which joins with other tables. A new trace flag 2453 is introduced to...
The forth approach uses SQL Server's ability to assign a table of data to a variable. This variable can then be treated like table name and used in an inner join. The queries look something like: DECLARE @IDHOLDER TABLE (id int primary key); ...
SQL Server优化的方法<一> 查询速度慢的原因很多,常见如下几种: 1、没有索引或者没有用到索引(这是查询慢最常见的问题,是程序设计的缺陷) 2、I/O吞吐量小,形成了瓶颈效应。 3、没有创建计算列导致查询不优化。 4、内存不足 ...
Temporary Tables And Table Variables In SQL 基本常识 1. 局部临时表(#开头)只对当前连接有效,当前连接断开时自动删除 2. 全局临时表(##开头)对其它连接也有效,在当前连接和其他访问过它的连接都断开时自动删除 3. 临时表就像普通表一样,它可以做索引等等 ...
查询计划中的联接顺序为 Table1、 Table2、 TableA、 TableB、 Table3。解析视图的索引与任何索引相同,仅当查询优化器确定在 SQL Server 的查询计划中使用索引视图有益时,SQL Server 才会选择这样做。索引视图可以在任何版本的 SQL Server 中创建。 在某些较早版本的 SQL Server 中,查询优化器会自动考虑索引视图...
About Service packs for SQL Server More Information When you use a table variable in a batch or procedure, the query is compiled and optimized for the initial empty state of table variable. If this table variable is populated with many ro...
9、DB Server 和APPLication Server 分离;OLTP和OLAP分离 10、分布式分区视图可用于实现数据库服务器联合体。联合体是一组分开管理的服务器,但它们相互协作分担系统的处理负荷。这种通过分区数据形成数据库服务器联合体的机制能够扩大一组服务器,以支持大型的多层 Web 站点的处理需要。有关更多信息,参见设计联合数据库服...