Re: Release Note Changes

Pavan Deolasee wrote:
>
>
> On Dec 8, 2007 3:42 AM, Andrew Dunstan <andrew(at)dunslane(dot)net
> <mailto:andrew(at)dunslane(dot)net>> wrote:
>
>
>
> Bruce Momjian wrote:
> > Andrew Dunstan wrote:
> >
> >>>> I still think this needs to be qualified either way. As it
> stands it's
> >>>> quite misleading. Many update scenarios will not benefit one
> whit from
> >>>> HOT updates.
> >>>>
> >>>>
> >>> Doesn't the detail description qualify it enought? The
> heading isn't
> >>> suppose to have all the information or it would be unreadable.
> >>>
> >>>
> >>>
> >> If you don't want to be more specific I'd say "certain updates"
> or "some
> >> updates" or something similar, just some flag to say it's not
> all of them.
> >>
> >
> > Good idea. I added "most":
> >
> > Heap-Only Tuples (<acronym>HOT</>) accelerate space reuse
> for most
> > <command>UPDATE</>s (Pavan Deolasee, with ideas from many
> others)
> >
>
> But that's not true either. For example, in my current $dayjob app not
> one significant update will benefit - we have an index rich
> environment.
> You have no basis for saying "most" that I can see. We really
> should not
> be in the hyp business in our release notes - that job belongs to the
> commercial promoters ;-)
>
>
>
>
> I don't agree completely. HOT updates is just one significant benefit of
> HOT and is constrained by the non-index column updates. But the other
> major benefit of truncating the tuples to their line pointers applies to
> HOT as well as COLD updates and DELETEs. This should also have
> a non trivial positive impact on the performance.
>
> There might be few scenarios where HOT may not show any improvement
> such as CPU-bound applications, but I am not sure if its worth mentioning.
>
>
> <http://www.enterprisedb.com>

Um, I don't understand. I freely admit that I haven't kept up with all
the nuances of the HOT discussions, but this bit has totally eluded me,
so please elucidate.

cheers

andrew