-How are nulls represented in data?
Pradeep Kamath 2010-08-09, 16:42
What value does hive expect in the data for a column to be treated as null? I tried some permutations on a text data based table but couldn't figure out what the correct representation was. I tried empty string, the string NULL and the string null for a string column and in all three cases the "is null" operator returned false.
A couple of related questions:
- Does the representation of null depend on the type of the column - is it different for string Vs non-string columns?
- Is the representation of null different for different storage formats - text Vs RCFile Vs SequenceFile - I am particularly interested in text and RCFile.
Thanks in advance,
Ning Zhang 2010-08-09, 18:46
yongqiang he 2010-08-09, 20:07