private boolean hasExternalSchema(Properties properties) {
    return properties.getProperty(AvroSerdeUtils.AvroTableProperties.SCHEMA_LITERAL.getPropName()) != null
        || properties.getProperty(AvroSerdeUtils.AvroTableProperties.SCHEMA_URL.getPropName()) != null;
  }
Read or write Avro data from Hive.
serde/src/java/org/apache/hadoop/hive/serde2/avro/AvroSerDe.java