[hodgesrm]

This can happen in data cleaning/loading where you load unclean data into a table that is ready for analysis. I have loaded data through staging tables regularly. There may be multiple stages.

Another example is materialized view creation. It's common for these to scan large quantities of data to compute aggregates.

[m0zg]

That's not the recommended way of loading data into BigQuery, though.

https://cloud.google.com/bigquery/docs/loading-data