Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin

On 2024-08-10 16:01:18 +0700, John Naylor wrote:
> On Tue, Aug 6, 2024 at 9:58 PM John Naylor <johncnaylorls(at)gmail(dot)com> wrote:
> >
> > It also turns out that to support 64kB memory settings, we actually
> > wouldn't need to change radix tree to lazily create memory contexts --
> > at least currently, SlabCreate doesn't allocate a keeper block, so a
> > newly created slab context reports 0 for "mem_allocated". So I'm
> > inclined to go ahead change the minimum m_w_m on v17 and master to
> > 64kB. It's the quickest and (I think) most future-proof way to make
> > this test work. Any objections?
>
> This is done. I also changed autovacuum_work_mem just for the sake of
> consistency. I did some quick math and found that there shouldn't be a
> difference between 32- and 64-bit platforms for when they exceed 64kB
> in the tid store. That's because exceeding the limit is caused by
> allocating the first block of one of the slab contexts. That
> independence may not be stable, so I'm thinking of hard-coding the
> block sizes in master only, but I've left that for another time.

Thanks a lot!

Greetings,

Andres Freund