The query uses temporary tables to act as spillable data structures. The durability guarantees WiredTiger provides make using temporary tables harder or less efficient for the use case. We can explore means to support a use case of temporary tables.

jordi.olivares-provencio@mongodb.com says the following are the requirements:

• Table-like interface
• No durability guarantees
• No timestamps support required

We could also consider the impact on the cache expected from having such a table. Whether the checkpoints would skip this table, etc.

I have this ticket here so that the slack conversation is not lost. If the ticket gets refined, some work might come out of it.