You have a directory named jobdata in HDFS that contains four files: _first.txt, second.txt, .third.txt and #data.txt.
How many files will be processed by the FileInputFormat.setInputPaths () command when it’s given a path object representing this directory?
A . Four, all files will be processed
B . Three, the pound sign is an invalid character for HDFS file names
C . Two, file names with a leading period or underscore are ignored
D . None, the directory cannot be named jobdata
E . One, no special characters can prefix the name of an input file
Answer: C
Explanation:
Files starting with ‘_’ are considered ‘hidden’ like unix files starting with ‘.’.
# characters are allowed in HDFS file names.