The following bug has been logged on the website:
Bug reference: 16468
Logged by: TAKATSUKA Haruka
Email address: harukat@sraoss.co.jp
PostgreSQL version: 13beta1
Operating system: Any
Description:
> Allow grouping sets to use hash aggregation with disk storage for large
> grouping set results (Jeff Davis)
>
> Previously, hash aggregation was avoided if it was expected to use
> more than work_mem memory. This is controlled by enable_hashagg_disk.
It seems to me that the "enable_hashagg_disk" is mistaken for
"enable_groupingsets_hash_disk".