Re: Alter or rename enum value - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Alter or rename enum value
Date
Msg-id 28167.1457543612@sss.pgh.pa.us
Whole thread Raw
In response to Re: Alter or rename enum value  (Andrew Dunstan <andrew@dunslane.net>)
Responses Re: Alter or rename enum value
List pgsql-hackers
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



pgsql-hackers by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: WIP: Upper planner pathification
Next
From: Robert Haas
Date:
Subject: Re: [PROPOSAL] VACUUM Progress Checker.