[Specification Clarification] Extra properties on Record Fields?

[Micah Kornfield <em...@gmail.com>]

It appears Schema objects are explicitly allowed to have additional
attributes as metadata [1]:

Attributes not defined in this document are permitted as metadata, but must
> not affect the format of serialized data.


However I don't see similar language for Field objects on records [2].  It
seems that at least the Python and Java implementation [3][4] passes
through extra attributes on the field objects.  I can't find similar code
in the C++ implementation.

Are extra attributes on Fields an option that should be supported across
implementations?  In practice are the extra attributes on fields used
differently then extra attributes on the schema?

Thanks,
Micah

[1] https://avro.apache.org/docs/current/spec.html#schemas
[2] https://avro.apache.org/docs/current/spec.html#schema_record
[3] https://github.com/apache/avro/blob/master/lang/py3/avro/schema.py#L920
[4]
https://github.com/apache/avro/blob/322ba39e68893745f0d40fb5ccc642756507898a/lang/java/avro/src/main/java/org/apache/avro/Schema.java#L1680