"If you think about it, there are lots of systems that do have this level of transaction processing. Think banking,
financial, trading and credit card systems"
I, at least, wasn't questioning this. What I was questioning was whether or not they were doing so with generalized RDBMS systems, as opposed to specialized systems.
The original banking transaction systems were non-SQL, non-RDBMS specialized transaction systems (that's where most of our theory on transaction processing comes from, too, i.e. two-phased commits and the like).
I had thought, but am not sure, that credit card systems were built atop the existing transaction processing infrastructure that already exists in the banking system.
I already mentioned SABRE.
If you know of any RDBMS (say Oracle) systems sustaining that level of throughput on three-table joins, I'm sure many of us here would be interested in hearing how that has been achieved. It's got to take a lot of work in terms of setting up the system architecture, hardware and software.
