Sometimes when you're downloading result sets in Looker using Google BigQuery Standard SQL or Google BigQuery as the database dialect, you will notice that an Allow large results button appears:
The reason for this is that BigQuery has a maximum response size for query results, as described in this article. Because of this maximum response size, a different process is required to successfully download results larger than this limit, which is described in this https://cloud.google.com/bigquery/docs/writing-results#large-results Google article.
If you choose All Results when you attempt to download a very large result set from Looker, the Allow large results button will show up as an option. This affects the download process in these ways:
- Looker will enable the
allowLargeResultsBigQuery option to true for the query.
- Looker will remove
ORDER BYclauses in the query.
- Looker will require a PDT Temp Schema with permission to write to it.
- Looker will store the results of the query in this temporary scratch schema under a random table name for one hour.