事务故障恢复的步骤是A．反向扫描日志文件、对每一个更新操作执_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

事务故障恢复的步骤是

A．反向扫描日志文件、对每一个更新操作执行逆操作，如此下去

B．对每一个更新操作执行逆操作、反向扫描日志文件，如此下去

C．正向扫描日志文件、对UNDO队列中的事务进行UNDO处理、对REDO队列中的事务进行REDO处理

D．正向扫描日志文件、对REDO队列中的事务进行REDO处理、对UNDO队列中的事务进行UNDO处理

答案

参考答案：A

解析：[命题目的] 本题主要考查了事务故障恢复的步骤。 [解题要点] 事务故障恢复的步骤：反向扫描日志文件、对每一个更新操作执行逆操作，如此下去。系统故障恢复的步骤：正向扫描日志文件、对UNDO队列中的事务进行UNDO处理、对REDO队列中的事务进行 REDO处理。 [考点链接] 掌握事务和日志的区别，以及事务故障恢复的步骤和系统故障恢复的步骤二者之间的区别。

填空题

Kofi Annan says helping survivors of last week’ s earthquake and (1) . in the Indian Ocean is (2) . The United Nations secretary-general says countnes that have offered aid must (3) and provide it. The offers add up to around (4) dollars. Unitd Nations officials say (5) of that is needed during the next six months.
The concern about offers of international aid is (6) . For example, the earthquake in Bam, Iran, in (7) of 2003 killed more than (8) people. Countries and groups offered hundreds of millions of dollars (9) . The United Nations says it has (10) only about (11) dollars in aid received so far. Governments and organizations that offered help (12) that, however.
On (13) Mr. Annan met with world leaders in Jakarta, Indonesia to discuss aid for (14) . The leaders discussed and (15) the idea of (16) owed by affected nations. But the leaders did not say they would do so. Some said that (17) to survivors would be more helpful.
Representatives of (18) countries and international organizations attended the meeting in Jakarta. Officials say they will cooperate to develop (19) for the Indian Ocean and the (20) .

填空题

农业标准化能促进（），改进农产品质量，增加产量，提高经济效益。