BI Engine SQL interface is currently supported in all regions where BigQuery exists

You no longer need to submit a form to get BI Engine acceleration. All you need to do is to create a BI Engine reservation for your project:
https://cloud.google.com/bi-engine/docs/reserving-capacity

Once a reservation is acquired, the qualified queries issued from your project are expected to be automatically accelerated.

Q & A
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1) Once a reservation is acquired, how long will it take BI Engine SQL interface to be enabled for my queries?
It will take up to 5 minutes for the BI Engine reservation changes to take effect.

2) Where can I get more information?
You can find more information about the BI Engine SQL interface in our public documentation: https://cloud.google.com/bi-engine/docs/sql-interface-overview

We also encourage you to join the discussion group to post questions and comments, and follow the latest updates: https://groups.google.com/g/bigquery-biengine-sql-preview-users

3) What is the cost of BI Engine SQL interface preview?
Pricing for the BI Engine's SQL interface is documented in the link below:
https://cloud.google.com/bi-engine/pricing