Tom Lane wrote:
>
> Even if the backend itself crashes, an uncommitted transaction will
> remain uncommitted, since no entry saying it's committed ever gets
> written to pg_log. Any tuples the dead backend did manage to write out
> will look like not-yet-committed tuples until the end of time.
>
> BTW, I am not sure whether VACUUM ever realizes it can reclaim those
> uncommitted tuples. To do that it'd have to make some kind of
It does.
Vadim