title: SPARK-HIVE-key differences between Hive and Parquet from the perspective of table schema processing
body: <p>I am new in spark and hive. I do not understand  the statement </p>
  
  <p>"Hive considers all columns nullable, while nullability in Parquet is significant"</p>
  
  <p>If any one explain the statement with example it will better for me. Thank your.</p>