Re: So, is COUNT(*) fast now?

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Fri, Oct 21, 2011 at 3:55 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>>> Anyhow, here's the scoop. On my desktop machine running F14, running
>>> SELECT sum(1) FROM pgbench_accounts in a tight loop, 60 s worth of
>>> oprofile data:
>>> 176830 13.0801 postgres postgres ExecProject

>> Hm, that's weird. In both these cases, I'd have expected that
>> ExecProject would get optimized away thanks to selection of a physical
>> tlist for the scan node. Wonder if that got broken ...

> If it did, it looks like it wasn't recent. I set up the same test
> case on my MacBook using REL9_1_STABLE and REL9_0_STABLE and set a
> breakpoint on ExecProject(). Both back-branches appear to also call
> ExecProject() for every tuple.

Oh, the ExecProject calls are coming from advance_aggregates().
Move along, nothing to see here ...

regards, tom lane