In T156869: Design a method for keeping user-created tables in sync across labsDBs we decided not to allow user created tables on the new Wiki Replica cluster. The reasoning for the decision is sound (can't guarantee replication and that blocks maintenance & load balancing).
There are a class of analytics-style queries that are much easier to do with an intermediary table however rather than a sub-select, union, or in-app join. Would it be reasonable to allow things like create temporary table foo ( foo_id varchar(30) ); to be performed on these servers? The upstream documentation says:
You can use the TEMPORARY keyword when creating a table. A TEMPORARY table is visible only within the current session, and is dropped automatically when the session is closed. This means that two different sessions can use the same temporary table name without conflicting with each other or with an existing non-TEMPORARY table of the same name. (The existing table is hidden until the temporary table is dropped.)