Thanks for the notes. I thought about using a prepared statement, but I cannot find any examples of using a PREPARE statement from within a function, and don't really feel like tinkering around to figure it out.
Performance is at the point where the Java/PHP bridge and JasperReports are bottlenecks. The run_time variable seldom goes beyond 2.6s now. The reports take about 5 - 6 seconds to appear. At this point I'm into diminishing returns.
I can perform a 60-minute hardware upgrade or spend 12 hours profiling to get less than the same net effect (and there is no guarantee I can improve the performance in fewer than 12 hours -- it took me 17 days and countless e-mails to this mailing group just to get this far -- thank you again for all the help, by the way). (If I was a PostgreSQL guru like most people on this list, it might take me 2 hours of profiling to optimize away the remaining bottlenecks, but even then the gain would only be a second or two in the database arena; the other system components will also gain by a hardware upgrade.)