The Single-database Model   

　　The single-database model has received considerably more attention than the multiple- database model．The focus of research into single-database model has been on addressing the twin problem of long waits and loss of work that the long duration of transactions brings about.   
　　The single-database model requires the intro-diction of a notion of database consistency, and protocols for concurrency control and recovery, that are different from those supported in traditional database systems．If a "reasonable" notion of database consistency is to be supported (I．c. the database system is to enforce it automatically), there are bound to be” conflict" situations where one transaction comes into an access conflict against some other transaction. If await is to be avoided，some means of a negotiated settlement of the conflict must be provided, thereby dragging the users into the details of concurrency control．The single-database model is more appropriate-ate than the multiple-database model in an environment where it is difficult to determine in advance logical partitions of the database that correspond to work to be performed, and the users closely cooperate.

翻译：

单一数据库模式 
  
　　单一数据库模式比多个数据库模式受到了更多的重视。研究单个数据库模式的焦点集中在长时间寻址等待和长期业务带来的工作损失该两个问题。
　　单一数据库模式要求引进数据库一致的观念和并行控制及恢复的协议，此协议不同于传统数据库系统中所支持的那些协议。如果一个数据库一致的合理观念要得到支持（即数据库系统要自动实行这个观念）、一定会有矛盾的情形产生、在这种情形中一个业务与其它业 务产生存取矛盾如果要避免等待，就必须提供某种协商解决矛盾的方法，从而迫使用户详细了解并行控制单一数据库模式在某一种环境中比多个数据库模式更恰当，在这个环境中，要事先确定与要执行的工作相适应的数据库的逻辑分割是很难的，同时用户们又紧密地合作在一起。