Minor Description
When a binary colunm is written into csv files, actual content of this colunm is object.toString(), which is meaningless.
val df = Seq(Array[Byte](1,2)).toDF df.write.csv("/Users/guowei/Desktop/binary_csv")
The csv file's content is as follows:
Meanwhile, if a binary colunm saved as table with csv fileformat, the table can't be read back successfully.
val df = Seq((1, Array[Byte](1,2))).toDF df.write.format("csv").saveAsTable("binaryDataTable")spark.sql("select * from binaryDataTable").show()
So I think it' better to change binary to unsupported dataType in csv format, both for datasource v1(CSVFileFormat) and v2(CSVTable).
