# Connect to BigQuery

> Set up a BigQuery connection in Holistics by creating a Google service account with the right IAM roles, generating a JSON key, and adding it as a data source.

[BigQuery](https://cloud.google.com/bigquery/) is Google's serverless data warehouse solution designed for analytics. 

In this document, we will walk you through the steps to 

- Create a service account for Holistics to interact with your BigQuery data
- Connect BigQuery to Holistics as a data source.

## Permissions required for the Service Accounts

You can check this [official docs from Google](https://cloud.google.com/iam/docs/understanding-roles?&_ga=2.153828155.-2035801214.1528358046#bigquery-roles) for the full list of BigQuery roles and permissions. 

Holistics needs some of these permissions to run on your BigQuery data warehouse. For a quick start, we recommend you to create a Google service account with the following roles:
- **BigQuery User** (to provide permissions to run jobs)
- **BigQuery Job User** (to execute queries)
- **BigQuery Data Viewer** (to get table metadata)

Or you can create a custom role that includes the following permissions: `bigquery.tables.getData`, `bigquery.jobs.create`, and `bigquery.tables.get`.

- If you also want to import, transform data/persist your models to your BigQuery, Holistics will need **permission to create/edit tables**. One of these roles will suffice:
  - **BigQuery Data Editor**
  - **BigQuery Data Owner**

## Steps
### Step 1: Create a Service Account for Holistics

- Go to [Google Cloud Console](https://cloud.google.com/) page. Create a new project if you are starting from scratch, or select an existing project that already contains data you need to model.

  

- From the left navigation bar, navigate to **IAM & Admin > Service Accounts** and click **CREATE SERVICE ACCOUNT**. 

  

  The service account allows you to control the features that Holistics has access to. Fill in the account details and click **Create**.

  

- Next, click **Select a role > BigQuery User** to grant permission to the account.

  

  More details about roles in [Google's official docs](https://cloud.google.com/iam/docs/understanding-roles?&_ga=2.153828155.-2035801214.1528358046#bigquery-roles).

  After that, click **Done** to finish the account setup. You now have a service account for Holistics to interact with your project. 

- Next, at the service account you have just created, click on **Actions > Create key** to create a private key for the account. **Key type** should be JSON.

  

  Download and store the JSON file in a safe location. This file will be used to connect your BigQuery account to Holistics.

### Step 2: Add Google BigQuery data source to Holistics

- From Holistics app's header bar, open **Organization Settings** menu -> **Data Sources**. 

  

- Click **New Data Source** button, and select **Google BigQuery** as the database type. Fill in the display name for the data source, and the project ID of your BigQuery project. The project ID can be found in the JSON key file.

  In the JSON credentials box, paste in the content of the JSON file downloaded in the previous step.

  

- Click on **Test connection** to ensure the connection works, and then **Save** to finish.

Now you can start using Holistics to import, transform, and model data in your BigQuery data warehouse.

## Settings
### Use Storage API
:::info Closed Beta
This feature is currently in Closed Beta!  
To register, please fill in this [form](https://form.jotform.com/230511857392457/prefill/662b5645333932a7fb2abae3f2fa).
:::

By enabling [BigQuery Storage API](https://cloud.google.com/bigquery/docs/reference/storage), Holistics can fetch query results upto **3 times faster**.