Re: Re: [COMMITTERS] pgsql: Recognize functional dependency on primary keys.

Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
>
>> OK, I put it back, but I still feel we might not need it anymore.
>>
>
> Even if you're willing to believe that the questions will stop once
> we have this feature, that won't happen for more than a year.
>

As a general comment on this, I've gotten two rounds of complaints about
MySQL migrations bit by this problem in the last year, and I found it
handy to point them to the FAQ entry. Even if one of the forms starts
to work in 9.1 eventually, I'd like to see a comment about this issue
hang around somewhere for future reference. Note that in both cases the
whole operation involved was rather brain dead and returning silly
indeterminate results in MySQL, but they didn't realize it. No
objections to the PostgreSQL "limitation" once they understood it was
fixing a subtle bug in the original too.

I was thinking of adding this one as an example for my next MySQL vs.
PostgreSQL paper update, it's a great example of the focus on
correctness differences between the two databases.

--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.us