Re: Removing more vacuumlazy.c special cases, relfrozenxid optimizations

On Sat, Feb 19, 2022 at 7:28 PM Andres Freund <andres@anarazel.de> wrote:
> If the vacuum can get the cleanup lock due to the adversarial patch, the
> heap_force_kill() doesn't do anything, because the first item is a
> redirect. However if it *can't* get a cleanup lock, heap_force_kill() instead
> targets the root item. Triggering the endless loop.

But it shouldn't matter if the root item is an LP_REDIRECT or a normal
(not heap-only) tuple with storage. Either way it's the root of a HOT
chain.

The fact that pg_surgery treats LP_REDIRECT items differently from the
other kind of root items is just arbitrary. It seems to have more to
do with freezing tuples than killing tuples.


--
Peter Geoghegan