This was also discussed at the last SQL WG meeting but was postponed for further refinement. But it’s likely to be added soon.

BigQuery has it! https://docs.cloud.google.com/bigquery/docs/reference/standa...

Yes it needs to be in the standard though.

That might be nice for manual experimentation, but for application use, this seems brittle compared to specifying the columns you really want to have and process.