InputFormat决策 [英] InputFormat Decision

问题描述

我试图找出哪些给出的答案最适合这个问题：

给定一个具有以下结构的文件目录：行号，
制表符，字符串：

Example ：

1abialkjfjkaoasdfjksdlkjhqweroij

<2> 2kadfjhuwqounahagtnbvaswslmnbfgy

3kjfteiomndscxeqalkzhtopedkfsikj

您希望将每行作为一条记录发送给Mapper。您应该使用哪个
InputFormat来完成该行：conf.setInputFormat
（____。class）; ？

A。 SequenceFileAsTextInputFormat

B。 SequenceFileInputFormat

C。 KeyValueFileInputFormat

D。 BDBInputFormat

我的分析： 选项A 是我发现存在的格式，但我不确定它的正确用法，并且它适合作为答案。

选项B 是不可能的，因为SequenceFiles是二进制数据（K，V）对二进制数据对的文件，因此不适合。

Option C 是不可能的，因为没有KeyValueFileInputFormat，虽然在这里，如果它是一个错字，并且它实际上是KeyValuetextInputFormat，比我认为它会是一个不错的选择。或者是不是？

选项D 是不可能的，因为没有BDBInputFormat，即使它是一个错字，它实际上是BDInputFormat比它不适合这种情况。

谢谢！
D

解决方案

答案是选项C 。它可能是一个错字

KeyValueTextInputFormat 可帮助您使用TAB分隔线。
因此行号将是关键字，字符串将是该值。

I am trying to figure out which of the given answers suits best the question:

Given a directory of files with the following structure: line number, tab character, string:

Example:

1abialkjfjkaoasdfjksdlkjhqweroij

2kadfjhuwqounahagtnbvaswslmnbfgy

3kjfteiomndscxeqalkzhtopedkfsikj

You want to send each line as one record to your Mapper. Which InputFormat should you use to complete the line: conf.setInputFormat (____.class) ; ?

A. SequenceFileAsTextInputFormat

B. SequenceFileInputFormat

C. KeyValueFileInputFormat

D. BDBInputFormat

My analysis:

Option A is a format I found to exist, but I'm not sure of the correct usage of it and if it suits as an answer.

Option B is not possible since SequenceFiles are file of binary data (K,V) pairs of binary data, and thus will not be suitable..

Option C is not possible because there is no KeyValueFileInputFormat, though here, if it is a typo and it actually is KeyValuetextInputFormat, than I think it will be a good choice. Or isn't it?

Option D is not possible because there is no BDBInputFormat and even if it is a typo and it actually is BDInputFormat than it wouldn't suit the case.

Thank You! D

解决方案

The answer is Option C. It may be a typo

KeyValueTextInputFormat helps you to get line splitted with TAB. So line number will be the key and the string will be the value.

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