Hbase table may contain blank column names & blank column family names. Drill needs to handle such situation.
I faced the issue when I had a column with blank column name in my Hbase Table. To reproduce it :
-Create a column without any name in Hbase
-Try to access it via Drill console
-Try to use CONVERT_FROM function to convert that data from Base64 encoding to make it readable. You wont be able to convert blank column because you cannot use blank in your query after a dot.
Something like this
SELECT CONVERT_FROM(students. , 'UTF8') AS zipcode
Where column name is blank
We need to provide a placeholder for blank column names