Cloudera
CCD-410 · Question #15
CCD-410 Question #15: Real Exam Question with Answer & Explanation
Sign in or unlock CCD-410 to reveal the answer and full explanation for question #15. The question stem and answer options stay visible for context.
Question
You write MapReduce job to process 100 files in HDFS. Your MapReduce algorithm uses TextInputFormat: the mapper applies a regular expression over input values and emits key- values pairs with the key consisting of the matching text, and the value containing the filename and byte offset. Determine the difference between setting the number of reduces to one and settings the number of reducers to zero.
Options
- AThere is no difference in output between the two settings.
- BWith zero reducers, no reducer runs and the job throws an exception. With one reducer, instances of
- CWith zero reducers, all instances of matching patterns are gathered together in one file on HDFS.
- DWith zero reducers, instances of matching patterns are stored in multiple files on HDFS. With one reducer,
Unlock CCD-410 to see the answer
You've previewed enough free CCD-410 questions. Unlock CCD-410 for full answers, explanations, the timed quiz mode, progress tracking, and the master PDF. Question stem and options stay visible so you can still see what's on the exam.