SiteWise avro file schema

Question

I understand from [this document](https://docs.aws.amazon.com/iot-sitewise/latest/userguide/file-path-and-schema.html#metrics-file-path-and-schema) all about how files in the cold tier are stored as S3 objects.  What I think is missing is the actual avro schema file needed to load these files into something like a local Jupyter notebook.  This schema file should look like this:

```
{
   "type" : "record",
   "namespace" : "Tutorialspoint",
   "name" : "Employee",
   "fields" : [
      { "name" : "Name" , "type" : "string" },
      { "name" : "Age" , "type" : "int" }
   ]
}
```

Is this schema the same for every SiteWise installation or does it depend on my model?  Is there a way to export it from my model or asset?  I just want to be able to peek through these files with my own software.

Answer

SiteWise exports the Avro Schema into the header of the exported .avro file, so no need to load a separate Avro schema when reading the file. Here a sample python script to read a SiteWise avro export and dumps the schema:
```
>>> from avro.io import DatumReader
>>> from avro.datafile import DataFileReader
>>> avro_reader = DataFileReader(open("/tmp/raw_a50553ae-184e-4cea-ba5a-847e6d76e4ac_c82738f4-d145-4b12-8b6a-
>>> avro_reader.meta
{'avro.schema': b'{"type":"record","name":"RawDatum","namespace":"amazon.aws.iot.sitewise.raw","fields":[{"name":"seriesId","type":"string"},{"name":"timeInSeconds","type":"long"},{"name":"offsetInNanos","type":"long"},{"name":"quality","type":"string"},{"name":"doubleValue","type":["null","double"],"default":null},{"name":"stringValue","type":["null","string"],"default":null},{"name":"integerValue","type":["null","int"],"default":null},{"name":"booleanValue","type":["null","boolean"],"default":null},{"name":"jsonValue","type":["null","string"],"default":null},{"name":"recordVersion","type":["null","long"],"default":null}]}', 'avro.codec': b'snappy'}
```

SiteWise avro file schema

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