[Роман Кошелев]

по методу setTmpData есть только одна запись в "Руководстве разработчика":

Temporary tables
Temporary tables are instantiated and "live" where data are first inserted. The first insert determines whether a table lives on the client or on the server. So it does not matter where, on the server or on the client, a temporary table is declared. Even when you write code like server static tmptable::createTable() that instantiates a table, the table still becomes a client temporary table if the first record is inserted from client code.

If a temporary table has a new dataset (setTmpData), the temporary table will afterwards live where the temporary table it's having it's data from are living.

Temporary tables are inserted and fetched remote as ordinary tables (caching, replication, "chunks").

Temporary tables are created as files in the local file system.

Hints
A temporary table should live on the tier where it is used.

If a temporary table is used on several tiers, the table should live on the tier where the largest number of inserts and updates is performed.