Readpast can only be specified in transactions operating at the read committed or repeatable read isolation levels 仅可在运行于read committed或repeatable read隔离级别的事务中指定readpast 。
When on is specified , transactions specifying the read committed isolation level use row versioning instead of locking 当指定为on时,指定read _ committed隔离级别的事务将使用行版本控制而不是锁定。
Read committed isolation using row versioning is enabled by setting the read committed snapshot database option on 将read _ committed _ snapshot数据库选项设置为on可启用使用行版本控制的已提交读隔离。
Specifies that read operations comply with the rules for the read committed isolation level by using either locking or row versioning 指定读操作使用锁定或行版本控制来遵循有关read committed隔离级别的规则。
If the database option read committed snapshot is on , the database engine does not acquire locks and uses row versioning 如果数据库选项read _ committed _ snapshot为on ,则数据库引擎不获取锁,并使用行版本控制。