Andreas Pflug <[EMAIL PROTECTED]> writes: > Well, to me it's not well-known that floating-point addition is not > associative, do I need to re-learn my math?
regression=# select (1.0::float8 + (-1.0::float8)) + 1.0e-20::float8; ?column? ---------- 1e-20 (1 row) regression=# select 1.0::float8 + ((-1.0::float8) + 1.0e-20::float8); ?column? ---------- 0 (1 row) regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html