To specify a connection to BigQuery, you’ll need to generate a service account keyfile, then pass the path to that file to your config.yml file, as shown below: 
  # required fields
  - name: bigquery_connection
    type: bigquery
    key_path: /path/to/key.json
    datasets:
      dataset_num_one:
        - "*" # all tables
      dataset_num_two:
        - "monthly_active_*" # regex filtered tables
      user_analytics:
        - "company_activity_analytics_summary_view" # one specific table

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Generating a keyfile

To generate a keyfile, follow these steps:
  1. Sign into the Google cloud console.
  2. Ensure that you have API enabled on the BigQuery API page.
  3. On the Service accounts page, choose your project and click the button that says “Create Service Account”.
  4. Choose a service account name and click “Create and continue”.
  5. Under “Select a role”, choose “BigQuery” and choose an appropriate role for your service account. As this will only be used locally by you, we generally recommend using the most permissive role, BigQuery Admin. Complete the creation of your service account.
  6. On the Service accounts page, select the service account you created and click on the ellipsis under the “Actions” column. Select Manage keys.
  7. On this next page, click Add key > Create new key. Select JSON in the modal and click “Create”. The key will be automatically downloaded in your browser.