Re: extensible enum types

Tom Lane wrote:
> Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> > Robert Haas wrote:
> >> I like the idea of being able to modify enums on the fly, but I'm
> >> skeptical of an implementation that won't always work. Maybe it's
> >> still better than what we have now, but it seems grotty.
>
> > I'd be perfectly happy to hear a reasonable alternative.
>
> Insert a sort order column into pg_enum, and rearrange the values in
> that whenever the user wants to add a new value in a particular place.
> You give up cheap comparisons in exchange for flexibility. I think lots
> of people would accept that tradeoff, especially if they could make it
> per-datatype.
>
> One point here is that you'd have to restrict the rearrangements so that
> the relative sort order of existing values never changes, else you break
> (for example) indexes on columns of that type.

Sorry to be commenting late, but don't most people want to add to the
end or beginning of the enum list, rather than in the middle, and can't
we support that already?

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ None of us is going to be here forever. +