Major Description
In SPARK-23372, we introduced a backwards incompatible change that would remove support for writing out empty or nested empty schemas in file based datasources. This introduces backward incompatibility for users who have been using a schema that met the above condition since the datasource supported it. Except for Parquet and text, other file based sources support this behavior.
We should either :
- Make it configurable to enable/disable writing out empty schemas
- Enable the validation check only for sources that do not support it - Parquet / Text
