On 18/12/2019 20:46, Mark Dilger wrote:
> On 12/18/19 10:06 AM, Simon Riggs wrote:
>> Just consider this part of the recovery toolkit.
>
> In that case, don't call it "read uncommitted". Call it some other
> thing entirely. Users coming from other databases may request
> "read uncommitted" isolation expecting something that works.
> Currently, that gets promoted to "read committed" and works. After
> your change, that simply breaks and gives them an error.
I agree that if we have a user-exposed READ UNCOMMITTED isolation level,
it shouldn't be just a recovery tool. For a recovery tool, I think a
set-returning function as part of contrib/pageinspect, for example,
would be more appropriate. Then it could also try to be more defensive
against corrupt pages, and be superuser-only.
- Heikki