Memo for Avro Schema

• Avro 1.4.0 Specification

Avro schema constraints

Nullable and default values

{
  "name": "AvroMapEntity",
  "fields": [
    {
      "name": "mapField",
      "type": [ "null",
        {
          "type": "map",
          "values": "int"
        }
      ],
      "default": null
    }
  ]
}