Trick question! "c" is a *field name*, not a type name, so the fullname is
either "a.d" or "d". Fields don't have fullnames.

But your question is still good. I don't think this is clear in the Avro
specification either. I asked avro-dev about this about a year ago and got
no response:
http://mail-archives.us.apache.org/mod_mbox/avro-dev/202103.mbox/%3cCAB6dobWX1=_fctgvgm-d5r17pv_69u27tdzvljmwc+aizow...@mail.gmail.com%3e

As I mentioned in that email, there are even more tricky cases than the one
you listed. What if the "a.b" schema definition is wrapped inside another
schema with an explicit "namespace" field? Like this:

{
  "type": "record",
  "name": "wrapper",
  "namespace": "wrapping"
  "fields": [
    {
      "name": "inside",
      "type": {
          "type": "record",
          "name": "a.b",
        "fields": [
          {
            "name": "c",
            "type": {
              "type": "record",
              "name": "d",
              "fields": []
            }
          }
        ]
      }
    }
  ]
}

Now is the interior one "a.d" (since "a.b" is a fullname, so it implicitly
creates a namespace of "a"), or is it "wrapping.d" (since that's the first
explicit namespace)?

The spec just says that when a type is named with dots in it (like "a.b"),
then it ignores any namespaces, but it doesn't say it creates one for all
children. I think implementations are inconsistent in how they handle this,
and it needs to be cleaned up in the spec.



On Mon, Dec 27, 2021 at 1:53 PM Brennan Vincent <bren...@umanwizard.com>
wrote:

> It is a.c
>
> > On Dec 27, 2021, at 9:42 AM, Askar Safin <safinas...@mail.ru> wrote:
> >
> > Hi. I'm writing Avro implementation in Rust for personal use. I have a
> question. Consider this Avro scheme:
> >
> > {
> >  "type": "record",
> >  "name": "a.b",
> >  "fields": [
> >    {
> >      "name": "c",
> >      "type": {
> >        "type": "record",
> >        "name": "d",
> >        "fields": []
> >      }
> >    }
> >  ]
> > }
> >
> > What is fullname of record "c"? "a.c" or "c"? I think Avro specification
> is vague about this and should be fixed. When I attempt to interpret Avro
> spec literally, I get to conclusion that the fullname is "a.c". But this
> contradicts to my common sense.
> >
> > ==
> > Askar Safin
> > http://safinaskar.com
> > https://sr.ht/~safinaskar
> > https://github.com/
>

Reply via email to