Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:
> Tom Lane wrote:
>> Couldn't creation and deletion of a toasted object within the same
>> transaction do it?
> I tried and couldn't find a way to cause one to appear. When a row is
> created, it has xmax=0 so when it's deleted the xmax can just be set to
> the deleting xact. And we don't ever update pg_toast rows, AFAIK.
Ah, nevermind, brain fade ... I was momentarily confusing this with
combo CIDs. Right, there are no updates or row locks taken on toast
table rows (unless someone were to do one manually?)
regards, tom lane