Thanks for this reference. I enjoy your blog, but haven't made the time to read all the archives somehow. Stuff doesn't stick very well when it isn't yet "needed" info besides.
I have seen overhead from 'raise notice' in small functions that are sometimes called many thousands of times in a single query, but hadn't done the test to verify if the same overhead still exists for raise debug or another level below both client_min_messages and log_min_messages. Using your examples, I saw about .006 ms for each call to RAISE DEBUG with a client/log_min as notice/warning.
