Re: Release Note Changes

Pavan Deolasee wrote:
>
>
> On Dec 8, 2007 3:42 AM, Andrew Dunstan <andrew@dunslane.net 
> <mailto:andrew@dunslane.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