Re: Clarify TIMING OFF behavior

Greg Smith <greg(at)2ndQuadrant(dot)com> writes:
> While chatting in #pedant today, I noticed that it's not clear that
> EXPLAIN (ANALYZE ON, TIMING OFF) will still collect the total runtime of
> the statement. Attached patch clarifies that. It also comments why the
> related code runs INSTR_TIME_SET_CURRENT in all cases. That's actually
> how I noticed that--a read through explain.c now could rightly wonder
> "why is it still collecting that bit of time info when TIMING is off?"

Applied with a little bit of further wordsmithing.

> There's an argument possible here that a third TIMING option besides
> ON/OFF should really exist, one that really doesn't do any timing at
> all. I don't think enough use cases for that exist to justify coding
> it.

Agreed. If you can't tolerate two gettimeofday calls per EXPLAIN,
you don't need a new EXPLAIN option ... you need new hardware.

regards, tom lane