| 1. | A program that will keep a centralized database of howto ' s for a help desk 该软件维护一个集中式的帮助信息数据库。 |
| 2. | Because centralized database has many innate disadvantages when applied to internet , the application of distributed database gets more and more popular 计算机网络的发展和信息的共享,使得分布式数据库的发展成为必然和热点。 |
| 3. | It is a very active research area in distributed database systems . there is difference between centralized database and distributed database , which distributed database needs data transportation 由于集中式数据库和分布式数据库的区别在于,分布式数据库需要站点间的数据传输。 |
| 4. | A signal switch may also send a query message to the signal control point , which acts as a centralized database for routing instructions , such as how to handle 800 / 888 calls 信号交换机也可以向信号控制点发送一个查询信息,该信号控制点起到路由指令(如怎样处理800 / 888对方付费电话)的集中化的数据库的作用。 |
| 5. | Classification based on distributed ecl is proposed in the dissertation , the improvements in time and complexity are expected . the promising approach can be used for centralized databases as well as distributed databases 这种方法不仅适用于大规模的集中式数据库,同时也能用于处理异构、分布式的数据库,具有很好的研究前景。 |
| 6. | The better way to avoid maintenance problems is to cache the wsdl in the centralized database and then periodically check the timestamp version number of the wsdl to see if a newer one is available 为避免维护上的麻烦,更好的一个办法就是把wsdl高速缓存在一个集中式数据库里,然后定期检查它的时间戳记/版本号,看看是否有一个更新的wsdl可用。 |
| 7. | Data is typically carried to their datacenters on public telecoms networks and navigates a number of central processing systems ( built on complex routed and switched networks ) before being stored in centralized databases ( see figure 3 ) 在存储到中心数据库之前,数据首先通过公共通信网络导向几个中心处理系统(建立在复杂的路由和交换网络之上) 。 |
| 8. | In addition , distributed database system contains more complex contents than centralized database system . this essay aims to research on the principle , design and realization technology of oracle distributed database system 另外,在查询处理、事务管理、数据的完整性与安全性等方面,分布式数据库系统比集中式数据库系统具有更复杂、更丰富的内容。 |
| 9. | In a domain , passwords and permissions are simpler to keep track of , since a domain has a single , centralized database of user accounts , permissions , and other network details . the information in this database is replicated automatically among domain controllers 而在域内,密码和权限就很容易跟踪,因为域里有一个包含用户帐户、权限和其他网络细节信息的中心数据库,此数据库的信息可在域控制器之间自动复制。 |
| 10. | As the application of distributed computing is used much more widely , distributed database becomes a significant part of information management it avoids a lot of disadvantages of conventional centralized database , and is applicable to many situations distributed database is a set of data which is the unity logic , but in fact these data is located on different sites it is of high availability , easy expansibility , high concurrency , high efficiency and etc in distributed system , data redundancy is a method to improve the speed of query and the availability of system distributed query should shield the lower level details of data redundancy from end users , distributed transaction should ensure data from disaccord this paper introduces basic conceptions of distributed database firstly , discusses distributed transaction and concurrent control , describes the development prototype mysql ’ s characters , architecture and executive mechanism , then shows the skeleton model of dpsql and exposes the strategy and algorithm of distributed query and distributed transaction , at last analyzes the extra expenses and response delay of distributed processes this paper exposes the implementation mechanism of distributed query and distributed transaction emphatically distributed query uses the strategy of “ read one , write a11 ” s0 in such a system if user ’ s requests are read - - only for the most part and the distribution of data redundancy is plausible , efficiency is very high distributed transaction uses two - 。 phase commit protocol to ensure the consistency of global data , which has less communication overhead 分布式查询需要向用户屏蔽数据冗余分散的底层细节,分布式事务处理要保证全局数据完整,这都是传统集中式数据库不曾面临的问题。本文首先介绍了分布式数据库的概念性问题;接着讨论了分布式事务涉及的定义及算法;然后描述了dpsql的原型mysql的特性、结构和执行机制;继而给出了dpsql的梗概模型,阐述了实现分布式查询和分布式事务处理的策略及算法;最后分析了进行分布式处理给系统增加的额外开销和客户端的额外响应延迟。本文重点描述了分布式查询和分布式事务处理的实现机制,分布式查询采用”读一个写全部”的本地优先策略,在读操作频繁的系统中,只要库的分布合理,单机效率极高,几乎无任何附加开销和延迟,而以整个系统的角度看来,吞吐量就更是优于单机系统;分布式事务处理采用两阶段提交协议,通信次数较少并能确实保证副本一致。 |