Resolution: Cannot Reproduce
I have a table with 300 columns.
When I select a query , some null columns are also returned.
This is the query that I used.
"select a,b from dfs.root.`/2016/1/17` where a=1"
For example in this query some columns are returned that "a" value is null.
I think null values are problems. Because when I add a condition to it like
"select a,b from dfs.root.`/2016/1/17` where a=1 and a IS NOT NULL"
there is not any change and still NULL values are returned.