Something else I intended to ask in the original post, but forgot:
What effect , if any , will the autovacuum setting have in this type of scenario ? Will performance be improved by disabling this ?
no, when you use temporary tables intensively - you must vacuum pg_catalog intensively - vaccum should be more aggressive and faster then a bloating of system catalog.
Probably you should to do REINDEX some system indexes more often than is usually.
Regards
Pavel
I assume that a vacuum process will be required on at least the pg_catalog due to dropping of temp tables during the process.