The new Add Spatial Join GP tool: How is the temporary join data stored?

[Bud]

Regarding the new Add Spatial Join geoprocessing tool in ArcGIS Pro 3.0:

Joins attributes from one feature to another based on the spatial relationship. The target features and the joined attributes from the join features will be joined. The join is temporary.

Out of curiosity, how is the temporary join data stored? Is it stored in RAM, the project file, or a temporary table in the db?

If we wanted to refresh the spatial join, how would we do it?

[DanPatterson]

I set a scratch workspace differing from the unset defaults, but it is there and can be persisted if you save it after.

Enter a traverse—ArcGIS Pro | Documentation

[DuncanHornby]

I've noticed this new tool and ESRI seemed to have replaced all mention of the classic Spatial Join tool in the UI with this new Add Spatial Join. Whilst not answering your question, more of an observation, but I have discovered at least one tool that fails with the output of Add Spatial Join and that's the split by attributes tool.

Seems odd that this apparent in-memory join is persisted in the scratch workspace as Dan shows, seems to defeat the purpose of it being in-memory!