I bought the book this AM.

I know the UNDO tablespace filling up is a problem because the Oracle
DBA insists it is. If there is no downside to this tablespace filling
up, then I have been mislead. Perhaps my terminology is wrong
regarding the "temporary" table. I create a table in the schema's
tablespace, run queries against it, and then drop it when I am done.
Thus, perhaps it is not a "temporary table" as defined in the
literature.

Regardless, I hope the chapter about the UNDO tablespace in the book
can illustrate how to construct queries, or form transactions, that do
not leverage the UNDO tablespace. This should keep my DBA from adding
gigs and gigs of space to the tablespace.

Also, thanks for all the responses. They were very helpful.