于 2013-09-03 08:15, David Johnston 回复:
> Jeff Davis-8 wrote
>> Is there any semantic difference between marking a constraint as
>> DISABLED and simply dropping it? Or does it just make it easier to
>> re-add it later?
>
David Johnston wrote:
> I cannot answer the question but if there is none then the main
> concern I'd
> have is capturing "meta-information" about WHY such a constraint has
> been
> disabled instead of dropped.
Drop/build and disable/enable constraint has no fundamental difference,
and could achieve the same purpose.What I do also more convenient for
the user.
Recording the disabled constraints is easier than recoding all the
constrains.
What's more, a lot of people ever asked about turing off constraint and
The sql2008 support this.So I think it's necessary in some ways.
> I guess this whole feature extends from the trigger disable feature
> that
> already exists. Given we have the one adding this seems
> symmetrical...
>
> I cannot really see using either feature on a production system (if
> following best practices) but I can imagine where they could both be
> helpful
> during development. Note with this usage pattern the
> meta-information about
> "why" becomes considerably less important.
>
> David J.
Wang Shuo HighGo Software Co.,Ltd. September 3, 2013