On 9/1/23 21:34, Melanie Plageman wrote:
Hi,
I noticed that VACUUM FULL actually does freeze the tuples in the
rewritten table (heap_freeze_tuple()) but then it doesn't mark them
all visible or all frozen in the visibility map. I don't understand
why. It seems like it would save us future work.
I have often wondered this as well, but obviously I haven't done
anything about it.
I don't see why the visibility map shouldn't be updated so that all of
the pages show all visible and all frozen for this relation after the
vacuum full.
It cannot just blindly mark everything all visible and all frozen
because it will copy over dead tuples that concurrent transactions are
still allowed to see.
--
Vik Fearing
