Re: WIP: generalized index constraints

On Tue, Sep 15, 2009 at 12:18 PM, Jeff Davis <pgsql(at)j-davis(dot)com> wrote:
> On Tue, 2009-09-15 at 22:52 +1000, Brendan Jurd wrote:
>> I'm just getting started reviewing this version now.  I noticed that
>> your patch seems to have been generated by git.  Are you hosting this
>> work on a public repo somewhere that I can pull from?
>
> I just requested a public repo. I will publish there as soon as its
> approved.
>
>> Also I think
>> the committers generally prefer context diffs (pipe it through
>> "filterdiff --format=context --strip=1") in submissions.
>
> Thanks, I will do that for my future patch submissions.
>
>> Regarding the documentation updates, I think you might want to add
>> some commentary to Chapter 11: Indexes -- perhaps add a new section
>> after 11.6 Unique Indexes to talk about general index constraints,
>> and/or update the wording of 11.6 to reflect your changes.
>
> Will do.
>
>> My eyes started to cross in the second sentence.  "Detect conflicts
>> symmetrically"?  I have actually *used* this feature successfully in
>> testing the patch, and I still don't know quite what to make of that
>> phrase.  You might need to dumb it down.
>
> Will do.
>
>> It might also be good to be a bit more explicit about the way the
>> choice of operators works.  It is the inverse of the logic used to
>> express an ordinary value constraint.  E.g., when you use the equality
>> operator in an index constraint you are in effect saying that new rows
>> MUST NOT satisfy this operator for any existing rows.
>
> I'll include that, thanks.
>
> I appreciate the quick feedback; I'll make these changes tonight.

Instead of calling these generalized index constraints, I wonder if we
oughtn't to be calling them something like "don't-overlap constraints"
(that's a bad name, but something along those lines). They're not
really general at all, except compared to uniqueness constraints (and
they aren't called generalized unique-index constraints, just
generalized index constraints).

I didn't realize understand what this was all for until I read Brendan's review.

...Robert