Re: Alter or rename enum value
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: Matthias Kurz <m.kurz@irregular.at>, pgsql-hackers@postgresql.org
Date: 2016-03-09T17:13:32Z
Lists: 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
Commits
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Relax transactional restrictions on ALTER TYPE ... ADD VALUE (redux).
- 212fab9926b2 12.0 landed
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Partially restore comments discussing enum renumbering hazards.
- c9e2e2db5c20 9.4.0 cited
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Allow adding values to an enum type created in the current transaction.
- 7b90469b7176 9.3.0 cited