Re: limiting hint bit I/O

On Tue, Jan 18, 2011 at 9:24 AM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
> a few weeks back I hacked an experimental patch that removed the hint
> bit action completely.  the results were very premature and/or
> incorrect, but my initial findings suggested that hint bits might not
> be worth the cost from performance standpoint.  i'd like to see some
> more investigation in this direction before going with a complex
> application mechanism (although that would be beneficial vs the status
> quo).

I think it's not very responsible to allege that hint bits aren't
providing a benefit without providing the patch that you used and the
tests that you ran. This is a topic that needs careful analysis, and
I think that saying "hint bits don't provide a benefit... maybe..."
doesn't do anything but confuse the issue. How about doing some tests
with the patch from my OP and posting the results? If removing hint
bits entirely doesn't degrade performance, then surely the
less-drastic approach I've taken here ought to be OK too. But in my
testing, it didn't look too good.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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