问题 单项选择题

联机分析处理(OLAP)中,“切片”的含义是()

A.选定多维数组的一个三维子集的动作

B.选定多维数组的一个二维子集的动作

C.改变一个页面显示的维方向

D.改变一个报告显示的维方向

答案

参考答案:B

解析:

OLAP支持管理决策人员对数据进行深入观察,多维分析,,多维分析是指以多维方式组织起来的数据采取切片、切块、旋转等各种分析动作,以求剖析数据,使分析者、决策者能从多角度、多侧面地观察数据库中的数据,从而深入地了解包含在数据中的信息、内涵。选定多维数组的一个二维子集的动作叫做切片,选定多维数组的一个二维子集的动作叫做切块,改变一个报告或页面显示的维方向叫做旋转。

填空题
单项选择题

Who is poor in America This is a hard question to answer. Despite poverty’s messiness, we’ve measured progress against it by a single statistic: the federal poverty line. In 2008, the poverty threshold was $ 21,834 for a four-member family with two children under 18. By 1his measure, we haven’t made much progress. Except for recessions, when the poverty rate can rise to 15 percent, it’s stayed in a narrow range for decades. In 2007—the peak of the last business cycle—the poverty rate was 12.5 percent; one out of eight Americans was "poor. " In 1969, another business-cycle peak, the poverty rate was 12.1 percent. But the apparent lack of progress is misleading for two reasons.

First, it ignores immigration. Many immigrants are poor and low skilled. They add to the poor. From 1989 to 2007, about three quarters of the increase in the poverty population occurred among Hispanics—mostly immigrants, their children, and grandchildren. The poverty rate for blacks fell during this period, though it was still much too high (24.5 percent in 2007). Poverty "experts" don’t dwell on immigration, because it implies that more restrictive policies might reduce U.S. poverty.

Second, the poor’s material well-being has improved. The official poverty measure obscures this by counting only pretax cash income and ignoring other sources of support. These include the earned-income tax credit (a rebate to low-income workers), food stamps, health insurance (Medicaid), and housing subsidies. Although many poor live hand to mouth, they’ve participated in rising living standards. In 2005, 91 percent had microwaves, 79 percent air-conditioning, and 48 percent cell phones.

The existing poverty line could be improved by adding some income sources and subtracting some expenses (example: child care). Unfortunately, the administration’s proposal for a "supplemental poverty measure" in 2011—to complement, not replace, the existing poverty line—goes beyond that. The new poverty number would compound public confusion. It also raises questions about whether the statistic is tailored to favor a political agenda.

The "supplemental measure" ties the poverty threshold to what the poorest third of Americans spend on food, housing, clothing, and utilities. The actual threshold not yet calculated—will probably be higher than today’s poverty line. Moreover, this definition has strange consequences. Suppose that all Americans doubled their income tomorrow, and suppose that their spending on food, clothing, housing, and utilities also doubled. That would seem to signify less poverty—but not by the new poverty measure. It wouldn’t decline, because the poverty threshold would go up as spending went up. Many Americans would find this weird., people get richer, but "poverty" stays stuck.

What produces this outcome is a different view of poverty. The present concept is an absolute one: the poverty threshold reflects the amount estimated to meet basic needs. By contrast, the new measure embraces a relative notion of poverty: people are automatically poor if they’re a given distance from the top, even if their incomes are increasing.

The author thinks the existing poverty line()

A. is a faithful measure of poverty

B. is not adequate as a measure

C. is not as good as the supplemental measure

D. should have been discarded long ago