Jeff Davis <pgsql(at)j-davis(dot)com> writes:
> What am I missing about EXPLAIN ANALYZE that is causing that much
> overhead?
Instrumentation overhead? In this case you've got 2 million more
gettimeofday() calls in the one case than the other, which says that
gettimeofday() takes about 1 microsecond on your machine, which is not
too surprising for typical consumer PC gear. See discussions in the
pghackers archives back in May or so ... we tried to cut the overhead,
and failed miserably :-(
regards, tom lane