大学四年土木专业规划:翻译翻译,计算机专业英语,急急急!

来源:百度文库 编辑:神马品牌网 时间:2024/04/27 15:33:22
1. Logging: In order to assure durability, every change in the database is logged separately on disk. The log manager follows one of several policies designed to assure that no matter when a system failure or “crash" occurs, a recovery manager will be able to examine the log of changes and restore the database to some consistent state. The log manager initially writes the log in buffers and negotiates with the buffer manager to make sure that buffers are written to disk (where data can survive a crash) at appropriate times.

2. Concurrency control: Transactions must appear to execute in isolation. But in most systems, there will in truth be many transactions executing at once. Thus, the scheduler (concurrency-control manager) must assure that the individual actions of multiple transactions are executed in such an order that the net effect is the same as if the transactions had in fact executed in their entirety, one-at-a-time. A typical scheduler does its work by maintaining locks on certain pieces of the database. These locks prevent two transactions from accessing the same piece of data inways that interact badly. Locks are generally stored in a main-memory lock table, as suggested by Fig. 1.1. The scheduler affects the execution of queries and other database operations by forbidding the execution engine from accessing locked parts of the database.
3. Deadlock resolution: As transactions compete for resources through the locks that the scheduler grants, they can get into a situation where none can proceed because each needs something another transaction has. The transaction manager has the responsibility to intervene and cancel (“roll-back" or “abort") one or more transactions to let the others proceed.

我的英语太差了,哪位专业人士可以帮帮忙啊,小妹的20分送上了!

1. 砍伐原木: 为了要保证耐久性,每个方面的改变资料库被在磁碟片上分开地伐木。 记录经理跟随一些政策之一设计保证没有事件当一个系统失败或者 " 坠毁 " 发生的时候,一位防卫经理将能够调查改变的记录而且修复到一些一致的州资料库。 记录经理最初在缓冲中写记录而且和缓冲经理商议确定缓冲被写到磁碟片 (在哪里资料能继续生存一坠毁) 在适当的时代。
2. 同作控制: 交易一定要似乎在隔绝方面执行。 但是在大多数的系统,在那里将在事实是许多交易立刻执行。 因此, scheduler(同作-控制的经理) 一定要保证多个交易的个别行动被执行在如此的一次序以致於净余的效果是相同的好像交易事实上执行在他们的全部, 一-在-一-时间。 典型的 scheduler 藉由在资料库的特定块上维持锁做它的工作。
3. 僵局决议:当交易经过锁为资源竞争哪一 scheduler 授与, 因为每个需要另外的事物交易,所以他们能进入没有人能著手进行的一种情形有。 交易经理有责任干涉而且取消 (" 卷物 - 向后地 " 或者 " 放弃 ") 一或者更多的交易让其余者著手进行。

1. 砍伐原木: 为了要保证耐久性,每个方面的改变资料库被在磁碟片上分开地伐木。 记录经理跟随一些政策之一设计保证没有事件当一个系统失败或者 " 坠毁 " 发生的时候,一位防卫经理将能够调查改变的记录而且修复到一些一致的州资料库。 记录经理最初在缓冲中写记录而且和缓冲经理商议确定缓冲被写到磁碟片 (在哪里资料能继续生存一坠毁) 在适当的时代。
2. 同作控制: 交易一定要似乎在隔绝方面执行。 但是在大多数的系统,在那里将在事实是许多交易立刻执行。 因此, scheduler(同作-控制的经理) 一定要保证多个交易的个别行动被执行在如此的一次序以致於净余的效果是相同的好像交易事实上执行在他们的全部, 一-在-一-时间。 典型的 scheduler 藉由在资料库的特定块上维持锁做它的工作。
3. 僵局决议:当交易经过锁为资源竞争哪一 scheduler 授与, 因为每个需要另外的事物交易,所以他们能进入没有人能著手进行的一种情形有。 交易经理有责任干涉而且取消 (" 卷物 - 向后地 " 或者 " 放弃 ") 一或者更多的交易让其余者著手进行。