SQL Server数据库查询速度慢常见的有以下几种
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(SQL Server database query speed is slow, the following are common.
1. no index or index is used. This is the most common problem of slow query, which is the defect of programming.
2.I/O has a small throughput, forming a bottleneck effect
3. does not create a column that causes the query to be not optimized)