Re: Alter or rename enum value

Andrew Dunstan <andrew@dunslane.net> writes:
> On 03/09/2016 11:07 AM, Tom Lane wrote:
>> I have a vague recollection that we discussed this at the time the enum
>> stuff went in, and there are concurrency issues?  Don't recall details
>> though.

> Rings a vague bell, but should it be any worse than adding new labels?

I think what I was recalling is the hazards discussed in the comments for
RenumberEnumType.  However, the problem there is that a backend could make
inconsistent ordering decisions due to seeing two different pg_enum rows
under different snapshots.  Updating a single row to change its name
doesn't seem to have a comparable hazard, and it wouldn't affect ordering
anyway.  So it's probably no worse than any other object-rename situation.
        regards, tom lane