Hi,
On 2020-08-11 21:55:32 +0300, Pavel Biryukov wrote:
> I don't see a problem with "wrapping around" - the row's xmin does not change
> with freeze (AFAIK). It changes when the row is modified.
> So event if you hold some entity (with current xmin) for a long time (enough
> for "wrap around") and then try to update it, it will update ok.
The problem isn't that it won't update ok, it is that it might update
despite there being another update since the RETURNING xmin.
s1) BEGIN;INSERT ... RETURN xmin;COMMIT;
s2) BEGIN;UPDATE .. WHERE xmin ...; COMMIT;
s*) WRAPAROUND;
s1) BEGIN;UPDATE .. WHERE xmin ...; COMMIT;
this could lead to s1 not noticing that s2 was updated.
- Andres
