Andrea Pierleoni created BEAM-2595: -------------------------------------- Summary: WriteToBigQuery does not work with nested json schema Key: BEAM-2595 URL: https://issues.apache.org/jira/browse/BEAM-2595 Project: Beam Issue Type: Bug Components: runner-dataflow Affects Versions: 2.1.0 Environment: mac os local runner, Python Reporter: Andrea Pierleoni Assignee: Thomas Groh Priority: Minor
I am trying to use the new `WriteToBigQuery` PTransform added to `apache_beam.io.gcp.bigquery` in version 2.1.0-RC1 I need to write to a bigquery table with nested fields. The only way to specify nested schemas in bigquery is with teh json schema. None of the classes in `apache_beam.io.gcp.bigquery` are able to parse the json schema, but they accept a schema as an instance of the class `apache_beam.io.gcp.internal.clients.bigquery.TableFieldSchema` I am composing the `TableFieldSchema` as suggested [here](https://stackoverflow.com/questions/36127537/json-table-schema-to-bigquery-tableschema-for-bigquerysink/45039436#45039436), and it looks fine when passed to the PTransform `WriteToBigQuery`. The problem is that the base class `PTransformWithSideInputs` try to [pickle and unpickle the function](https://github.com/apache/beam/blob/master/sdks/python/apache_beam/transforms/ptransform.py#L515) (that includes the TableFieldSchema instance) and for some reason when the class is unpickled some `FieldList` instance are converted to simple lists, and the pickling validation fails. Would it be possible to extend the test coverage to nested json objects for bigquery? They are also relatively easy to parse into a TableFieldSchema. -- This message was sent by Atlassian JIRA (v6.4.14#64029)