Brent Ozar busts out the calculator:
You’re tuning a Postgres query and you’ve been told to run EXPLAIN with the BUFFERS option, like this:
EXPLAIN (ANALYZE, COSTS, VERBOSE, BUFFERS)But the output like this is confusing, because the numbers don’t add up vertically or horizontally. It’s just a whole mess of numbers that seem unrelated:
Read on to learn more about which numbers to pay attention to and what they all mean.