"Bryan White" <bryan(at)arcamax(dot)com> writes:
> Top tells me the front end process is using 5 to 10 percent of the CPU and
> the back end is using 10 to 20 percent. The load average is about 1.0 and
> the CPU is about 80% idle.
It's probably waiting for disk I/O ...
What does EXPLAIN tell you about how the queries are being executed?
Do you by any chance have the 6.5.3 system still available to compare
its EXPLAIN output?
regards, tom lane