BigQuery: pyarrow warning about schema argument

[tswast]

samples/tests/test_query_to_arrow.py::test_query_to_arrow
/tmpfs/src/github/google-cloud-python/bigquery/google/cloud/bigquery/_pandas_helpers.py:383: FutureWarning: Schema passed to names= option, please pass schema= explicitly. Will raise exception in future
return pyarrow.RecordBatch.from_arrays(arrays, column_names)

[les69]

Hello everyone! I'm experiencing the same issue non-deterministically and it seems to be linked to a reduction in the downloading performance (from ~200k rows per second to ~20k).
Is there any workaround for the moment?

Thank you

[plamut]

@les69 In which pyarrow version does that happen? Does it also happen in an earlier version, e.g. 0.14.1 (i.e. the performance regression, not the warning)?

The warning itself seems pretty benign, it's just the way parameters are passed to one of the pyarrow's methods, and pyarrow resolves that on its own (but will eventually stop doing that).

It might be, however, that performance is different when using a pyarrow schema as opposed to just the column names (source), and the distinction between these two cases became more visible with the warning introduced in pyarrow 1.15.0.