On Jan 24, 2016, at 9:01 PM, Charles Clavadetscher <clavadetscher(at)swisspug(dot)org> wrote:
> What is the point of having a check constraint that is not checked?
Well, it *is* checked going into the future; it's just not checked at the time the constraint is added. Ultimately, you do want to fix the data, but this makes it a two-step process, and reduces the time the table is locked against access.