Using Cloud Dataflow, this trivial Java application reads a table in BigQuery, and turns it into one file in GCS (GZIP compressed format). Why? Because currently BigQuery only support unsharded exports of under 1 GB.
https://cloud.google.com/bigquery/docs/exporting-data https://cloud.google.com/dataflow/
It uses the default credentials set to the environment variable GOOGLE_APPLICATION_CREDENTIALS. See all about that here: https://developers.google.com/identity/protocols/application-default-credentials
In the code, change the table name and bucket details etc. to suit your needs. You will also just need to create the GCS bucket(s) yourself. I wasn't bothered making them cli parameters.
To run:
--project=<your_project_id> --runner=DataflowRunner --jobName=bigquery-table-to-one-file --maxNumWorkers=50 --zone=australia-southeast1-a --stagingLocation=gs://<your_bucket>/jars --tempLocation=gs://<your_bucket>/tmp
It should look like this when it's running. I tested it with the public WIKI table (1 billion rows & ~100GB) and it took about 6 hours using 50 n1-standard-1 workers:
