External tables are available only on workspaces that run in your own Google Cloud project (customer-hosted GCP), on Growth plans and above. They are not available on AWS or on Nekt-hosted workspaces.
How it works
Nekt does not move your data. It registers a reference to the source table and reads it where it lives. Nothing is copied into Nekt’s storage, and you keep control of the source in your own project — Nekt only ever reads it.Add an external table
From the Catalog, pick the layer or folder where you want the table, open the New menu, and choose External table. A wizard walks you through two phases.1
Describe the source
Fill in the Google Cloud project the table lives in (yours, not Nekt’s), the Dataset, and the Table. Choose a Name in the Nekt catalog — use only lowercase letters, numbers, and underscores, and start with a letter.Datasets you have already shared with Nekt appear in the list. If you haven’t shared one yet, type its name and it will appear once the grant in the next phase is in place.
2
Grant access in Google Cloud
Complete a few steps in your own Google Cloud console. Nekt only checks these — it never changes permissions in your project. Each step is verified before the next one appears.
- Give Nekt read access to the source. Grant the Nekt service account shown in the wizard the BigQuery Data Viewer role on the source dataset. (Granting it on the table alone also works, but then Nekt cannot list the dataset’s tables and you type the table name by hand.)
- Enable queries across regions (only if the source is in another region). Run the SQL statements the wizard provides in BigQuery. They take a few minutes to take effect.
- Authorize the view. In the BigQuery console, open the source dataset (not the table) → Sharing → Authorize views, and add the view Nekt created in the previous step. BigQuery only authorizes views at the dataset level.
If the source table is in a different region from your workspace, queries that read it take noticeably longer, because the data has to cross regions. Nothing is wrong — if it becomes a problem, bringing the data in with a Source is faster.