It’s the usual way of saving a Dataframe as avro file,
Without explicitly specifying compression:
The above line led to the log:
18/03/20 10:26:16 INFO AvroRelation: using snappy for Avro output
18/03/20 10:28:33 INFO AvroRelation: writing Avro out uncompressed
If you are using itversity labs, you would be able to find this line in the logs below, just after you run the line of code.