Re: VACUUM FREEZE vs plain VACUUM

On Fri, 2025-07-18 at 06:31 +0200, Laurenz Albe wrote:
> On Thu, 2025-07-17 at 18:03 -0400, Ron Johnson wrote:
> > Does VACUUM FREEZE do something extra or special than to defer autovacuum
> > for an extra 50,000,000 transactions?
>
> To answer your question: the extra thing it does is that it even visits
> table pages that have the all-visible flag set, that is, they contain no
> dead tuples.  That means that it will do more work and use more
> of your system's resources.

... and the biggest impact is that it will modify more tuples, some of them
unnecessarily (because they will be deleted or updated before they reach
an age of 50 million transactions), and that will cause more writing
disk I/O on your system.

Yours,
Laurenz Albe