schema upgrade tool is failing with NPE while executing "SELECT 'Upgrading MetaStore schema from 1.2.0 to 2.0.0' AS ' '". The header row (metadata) is coming with rows having value null. This is causing null pointer access in function TableOutputFormat::getOutputString when row.values[i] is accessed. Instead of " AS ' ' ", if some other value like "AS dummy" is given, it's working fine. The issue is coming with mysql version 5.7 and above.