I was going through the practical exam for HDPCD in AWS. There is a question in pig as
"Remove all rows in the flightdelays data where the
DepTime column equals the string "NA".
The answer provided for this question says:
b = filter a by (chararray) $4 != 'NA' or (chararray) $11 != 'NA';
I do not understand why It checks 2 fields here. Is it correct or am I missing something ? Because of this I find differences in the actual output and my answer.
Please help me to understand if anyone has idea about it.