Exclusive locks prevent access to a resource by concurrent transactions 排他锁( x锁)可以防止并发事务对资源进行访问。
Shared locks allow concurrent transactions to read select a resource under pessimistic concurrency control 共享锁( s锁)允许并发事务在封闭式并发控制(请参阅
Conversely , a query holding a sch - s lock blocks a concurrent transaction that attempts to acquire a sch - m lock 相反,持有sch - s锁的查询将阻塞尝试获取sch - m锁的并发事务。
When one transaction holds a lock on an item , no concurrent transaction can read and / or modify this item 当一个事务对一个数据拥有了锁,那么其他并发事务则无法对它进行读或者写。
Because of this , queries are blocked when a concurrent transaction holds a sch - m schema modification lock on the table 因此,当并发事务持有表的sch - m (架构修改)锁时,将阻塞查询。
A transaction is a unit of isolation and each occurs separately and independently of concurrent transactions 事务是一个隔离单元,并发事务中的每个事务在发生时都相互分离,彼此独立。
Modifications made by concurrent transactions must be isolated from the modifications made by any other concurrent transactions 由并发事务所作的修改必须与任何其他并发事务所作的修改隔离。
Imagine that two concurrent transactions both read a row , one writes to it and commits , and then the second writes to it and commits 有两个并发事务同时读取同一行数据,然后其中一个对它进行修改提交,而另一个也是修改提交。
In addition , it brings forward the method to the concurrent transactions " s cooperative process , solve the underlying conflication problems 另外,在协议栈的实现过程中,对多个并发事务的协调处理提出了自己的解决思路,有效地克服了潜在的会话冲突问题。
The microsoft sql server database engine locks resources using different lock modes that determine how the resources can be accessed by concurrent transactions Microsoft sql server数据库引擎使用不同的锁模式锁定资源,这些锁模式确定了并发事务访问资源的方式。