@kunzel_paulo Hi. I'm afraid there is a technical error in the article. It is written that the collection data is stored in RAM and not in a physical table. As far as i know, collection data is stored in 2 tables in the APEX schema. (WWV_FLOW_COLLECTIONS$, WWV_FLOW_COLLECTION_MEMBERS$).
@PHoinkis @plamen_9 In addition, I would possibly add the CASE to the ORDER BY clause to more precisely express what the CASE stands for. This would also allow the MIN(id) to still be used.