performance of temporary vs. regular tables

Greetings,

in
http://archives.postgresql.org/message-id/1056648218.7041.11.camel@jester,
it is stated that the performance of temporary tables is "the same as a
regular table but without
WAL on the table contents.".

I have a datamining-type application which makes heavy use of temporary
tables to stage (potentially large amounts of) data between different
operations. WAL is write-ahead

To effectively multi-thread this application, I (think I) need to switch
from temporary to regular tables, because
- the concurrent threads need to use different connections, not cursors,
to effectively operate concurrently
- temporary tables are not visible across connections (as they are
across cursors of the same connection)

Thus, I wonder how much this will affect performance. Access on the
temporary table is inserting (millions of) rows once in a single
transaction, potentially update them all once within a single
transaction, then select on them once or more.

Of course, eventually loosing the data in these tables is not a problem
at all. The threads are synchronized above the SQL level.

Thanks for any input on how to maximize performance for this applicaiton.

Joachim