Code review comment for lp://staging/~jpds/launchpad/fix_361650

> I don't much like the column name either, but it does match the domain
> language used at http://www.ubuntu.com/getubuntu/mirror/1 so I guess it is
> correct.
>
> Why are we limiting things to one official country mirror per country? Is
> there a technical issue we need to ensure doesn't happen, or is this an
> arbitrary choice made by us or the mirror maintainers?
>
> Patch number is patch-2207-23-0.sql. Its good to land if you can confirm that
> the UNIQUE constraints are actually desirable.

One thing that needs changing - You should use 'IS TRUE' and 'IS FALSE' rather than '= TRUE' or '= FALSE'. = and IS give different results in SQL's three valued boolean arithmetic which can confuse the query planner since it isn't as smart as you.