Make existing bigquery table clustered

Question

I have a quite huge existing partitioned table in bigquery. I want to make the table clustered, at least for the new partition.

From the documentation: https://cloud.google.com/bigquery/docs/creating-clustered-tables, it is said that we are able to Creating a clustered table when you load data and I have tried to load a new partition using clustering fields: job_config.clustering_fields = ["event_type"].

The load finished successfully, however it seems that the new partition is not clustered (I am not really sure how to check whether it is clustered or not, but when I query to that particular partition it would always scan all rows).

Is there a good way to make clustering field for an existing partitioned table?

Any comment, suggestion, or answer is well appreciated.

Thanks a lot, Yosua

Answer 1

BigQuery supports changing an existing non-clustered table to a clustered table and vice versa. You can also update the set of clustered columns of a clustered table.

You can change the clustering specification in the following ways:

Call the tables.update or tables.patch API method.

Call the bq command-line tool's bq update command with the --clustering_fields flag.

Reference

https://cloud.google.com/bigquery/docs/creating-clustered-tables#modifying-cluster-spec