Protect a regional BigQuery table updated multiple times per day against regional failure with RPO under 24 hours while minimizing cost.

Exporting the table daily to a dual/multi-region Cloud Storage bucket provides disaster recovery for regional failure with an RPO (Recovery Point Objective) under 24 hours, as data is backed up daily. Storing in Cloud Storage is cost-effective compared to active BigQuery datasets. A dual/multi-region bucket ensures data availability even if one region fails. Daily copying the dataset to a backup region would be more expensive as it involves maintaining an active BigQuery dataset in another region. Taking a daily BigQuery snapshot is good for point-in-time recovery within the same region but doesn't protect against regional outages. Updating ETL to write to both regions would be the most expensive and complex option, involving significant architectural changes and continuous data replication costs.