SELECT constant; takes 15x longer on 9.0?

Hackers,

Continuing the performance test:

DBD, like a number of monitoring systems, does "pings" on the database
which look like this:

SELECT 'DBD::Pg ping test';

In our test, which does 5801 of these pings during the test, they take
an average of 15x longer to execute on 9.0 as 8.4 ( 0.77ms vs. 0.05ms ).

Any clue why this would be?

--                                  -- Josh Berkus                                    PostgreSQL Experts Inc.
                        http://www.pgexperts.com