On Dec 8, 2007 3:42 AM, Andrew Dunstan <
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)
>
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.
Thanks,
Pavan
--
Pavan Deolasee
EnterpriseDB
http://www.enterprisedb.com
