Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> wrote:
> heap_insert() calls CheckForSerializableConflictIn(), which checks if
> there is a predicate lock on the whole relation, or on the page we're
> inserting to. It does not check for tuple-level locks, because there
> can't be any locks on a tuple that didn't exist before.
>
> AFAICS, the check for page lock is actually unnecessary. A page-level
> lock on a heap only occurs when tuple-level locks are promoted. It is
> just a coarser-grain representation of holding locks on all tuples on
> the page, *that exist already*. It is not a "gap" lock like the index
> locks are, it doesn't need to conflict with inserting new tuples on
the
> page. In fact, if heap_insert chose to insert the tuple on some other
> heap page, there would have been no conflict.
Absolutely correct. Patch attached.
-Kevin