查询词典 serializability

On the basis of this,an XPath-based Locking protocol,as well as a lock mode,is put forward and then the schedule within the locking protocol mentioned above is proved to be serializability.

最后通过实验对XPL协议的并发性能进行测试和分析。

The features of transaction in multidatabase systems are analyzed, and the necessity to keep the global serializability when concurrency control of transaction processing in multidatabases is emphasized.

分析了多数据库系统中事务的特征，指出多数据库事务处理的并发控制问题需保持全局可串行化，即要求在各局部场地局部事务的执行不违反全局的执行次序。

In order to improve the efficiency of DBMS, Concurrent Control is the basic requirement on concurrent transactions execution. When transactions execute instantaneously, Lock Mechanism which could ensure transaction serializability is a good way. But the problem that LM produces should be faced.

并发控制是数据库管理系统提高运行效率的基本要求，事务并发执行时，采用锁机制是保证事务可串行化的一个方法，但因此而产生的死锁问题是一个必须面对的问题，其根本原因是由于数据共享的要求而造成的。

Firstly, the definition of cooperative transactions is given and the states of them are specified. Secondly, the dependencies among cooperative transactions and those between cooperative transactions and outside environments are specified in terms of states of cooperative transactions. Finally, the serializability correctness criterion for the presented model is specified by state dependencies of cooperative transactions.

首先给出了协同事务的定义，并描述了协同事务的状态，然后从协同事务的状态角度刻画协同事务之间、协同事务与外部环境之间的复杂依赖关系，最后用协同事务的状态依赖描述了可串行化正确性准则。

Serializability may not be implemented using only row-level locks; there must be another mechanism that prevents a newly inserted row from becoming visible to a transaction that has already executed a query that would return the row.

如果仅仅通过"行级锁"是无法实现事务序列化的，必须通过其他机制保证新插入的数据不会被刚执行查询操作的事务访问到。

The extended transactions are executed by the LDBMS on the local database and the specially generated control tables. These extended transactions are responsible for the global serializability and recovery of transactions.

局部数据库管理系统在局部数据库和控制表之上执行扩展事务，这些扩展事务负责维护全局可串行性及事务的恢复。

Global transaction management Global transaction management consists of global serializability, global atomicity and recovery, global deadlock checker, etc. In distributed data resources management, the complexity of local data sources increases the difficulty of global transaction management.

分布数据资源管理中的全局事务管理通过对事务管理的关键问题的分析，针对分布数据资源管理中数据源在事务处理能力中的巨大差异，提出了给每一个局部数据源包装器添加一些事务处理的功能，让包装器针对特定数据源的具体情况完成部分全局子事务的并发控制和恢复管理，使得在全局管理层可以使用二阶段锁进行并发控制和使用二阶段提交进行事务恢复，并使用超时法进行死锁检测，从而达到分数据资源的全局事务管理。

In addition, a new synchronization scheme, Double-Timestamp Transaction-Level Synchronization model is put forward to solve the synchronization problem under the 3-tier replication architecture (Mobile Client - Synchronization Server - Database Server). DTSTLS utilizes a novel double-timestamp strategy to promote the efficiency of synchronization. Besides, it ensures serializability and consistency of the mobile database system through transaction-level conflict reconciliation.Mobile transaction processing is another key technology to provide efficient information service in mobile computing environment.

通过引入一种乐观并发控制方法与两段锁协议相结合的移动事务处理机制，本文重点解决了交互式长事务的问题，并提供了对移动主机任意移动性和数据库系统一致性的支持；在移动对象数据库方面，本文提出了一种新的移动对象数据库模型—离散时空轨迹移动对象数据库模型，重点阐述了DSTTMOD模型中的位置表示方法及位置更新处理策略，并分别给出了基于GRID文件和基于QUAD树的移动对象索引算法。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。