Re: Release Note Changes

On Fri, 2007-12-07 at 12:33 -0500, Bruce Momjian wrote:
> Simon Riggs wrote:
> > On Fri, 2007-11-30 at 09:49 +0000, Gregory Stark wrote:
> > > "Simon Riggs" <simon(at)2ndquadrant(dot)com> writes:
> > >
> > > > If people understand there aren't 13 performance improvements there are
> > > > at *least* 19+ that is a positive message to help people decide to
> > > > upgrade.
> > >
> > > Frankly I think the release notes are already too long.
> >
> > So why do we have stuff in there that the users will never see?

Thanks for your reply.

> Which release note items?

Most of the stuff in Source Code would fall into that category. I don't
advocate removing those items, but I don't see the argument that space
is so tight in the release notes that we have to remove important
performance items but keep those.

> > We already have a release summary, so why summarise *some* of the detail
> > as well, but not all of it???
> >
> > I see no reason to diminish yours, Heikki's or my own contributions, all
> > of which were in the area of performance, which people do care about.
> > None of the ones I mentioned were trivial patches, nor were their
> > effects small.
>
> I totally agree that we are unfair in how we give attribution in the
> release notes.

I do understand that the release notes are there to inform the user and
not directly to give credit.

Some important items have been removed from the release notes. It took
me a whole month to notice, but I did eventually notice because I'm
familiar with my own work, as well as that of people working on closely
related items. I have, when I have been aware of them, pointed out
patches produced by others that I thought were missing.

> There is no weight given to patch difficulty and people
> who produce user-invisible changes are much less likely to be mentioned
> in the release notes.

The reward system drives the outputs. If trivial feature additions are
what we reward, then that's what we'll get. That's not important right
now and discussing that is not why I started this thread.

> I don't see any way to fix this that would not harm the release notes
> themselves. As I mentioned in an earlier email the release notes are
> designed to highlight user-visible changes in a user-understandable way.
> The mentioning of people who wrote the patches is merely a side-effect
> of that to give some credit, but it is a side-effect, not the main
> reason we mention something in the release notes.

Perhaps we are talking about different things. I'm discussing whether
something is important and you seem to be imagining that I only want to
see the phrase "(Simon)" lots of times. If that was the case, it would
have been very simple to arrange, yet I seem to have elected the most
difficult route to doing that. I could easily have hoovered up a few
more trivial changes if that was my line of thinking. So it clearly
wasn't.

Maybe the importance of the patches that were removed wasn't clear
enough, so let me explain my viewpoint. On another part of this thread I
summarised the feedback from others to a list of features that were
definitely user noticeable. The list was:

- Merge Join performance has been substantially improved when low number
of duplicate join keys exist on the outer side of the join (Simon, Greg)

- Large I/O reduction during recovery when full_page_writes = on
(Heikki)

- WAL file switch performance has been improved. Recovery startup now
refers to the last checkpoint time, which may be anything up to the
checkpoint_timeout interval before a database crash. (Simon, Tom)

The last one seems important to me, but I can see that might be TMI for
some people, though I feel we should document it somewhere. The other
side of that is that many people know about those response time spikes
and they will be very keen to know their cause was identified and
removed.

Those items have resulted in important performance gains, not just a few
percentage points. The first one can be 50% or more, the second one is
100% gain and the last one reduced response time spikes on busy systems
by something like a second at switch time. I wouldn't dare to mention
these things if the effects were small, but they are massive gains.

> If people are concerned about the unfairness, and I understand that, the
> best solution is not to add more items to the release notes to be more
> fair, but to remove all names from release note items.

That makes no sense, but it would benefit people that wrote fewer
patches, I guess.

--
Simon Riggs
2ndQuadrant http://www.2ndQuadrant.com