Re: Why is the comparison between timestamp and date so much slower then between two dates

Thomas Kellerer <spam_eater@gmx.net> writes:
> So my question is: why is comparing a timestamp to a date so much slower?

The date has to be up-converted to a timestamptz (not timestamp).
I think the expensive part of that is determining what timezone
applies, in particular whether DST is active.  You could try it
with "localtimestamp" (no parens) instead of "now()" to see how
it performs with a non-tz timestamp.

            regards, tom lane