Network latency can make chattiness a problem. More generally I think that not using PL/SQL leads to chattiness and literals. Then parse can become a problem and an expense.

In PeopleSoft that would be close to 100%! I can't think of a practical use of such a ratio. Chatty apps usually aren't instrumented so can't identify chattiest parts.

Perhaps parse is the critical metric?

I was always impressed how well PeopleSoft could perform, given how badly it behaves. No PL/SQL, just a stream of SQL. Often dynamically generated with literals. HR with Time&Labor and Payroll on a pay week was always fun.

I have a memory that the RAC and AA keys would both open boxes for both organisations.

We had a Commodore PET at school in about 1981. Those were the days.