Re: [PoC] Improve dead tuple storage for lazy vacuum

On Tue, Jul 19, 2022 at 1:30 PM John Naylor
<john(dot)naylor(at)enterprisedb(dot)com> wrote:
>
>
>
> On Tue, Jul 19, 2022 at 9:11 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> > I’d like to keep the first version simple. We can improve it and add
> > more optimizations later. Using radix tree for vacuum TID storage
> > would still be a big win comparing to using a flat array, even without
> > all these optimizations. In terms of single-value leaves method, I'm
> > also concerned about an extra pointer traversal and extra memory
> > allocation. It's most flexible but multi-value leaves method is also
> > flexible enough for many use cases. Using the single-value method
> > seems to be too much as the first step for me.
> >
> > Overall, using 64-bit keys and 64-bit values would be a reasonable
> > choice for me as the first step . It can cover wider use cases
> > including vacuum TID use cases. And possibly it can cover use cases by
> > combining a hash table or using tree of tree, for example.
>
> These two aspects would also bring it closer to Andres' prototype, which 1) makes review easier and 2) easier to preserve optimization work already done, so +1 from me.

Thanks.

I've updated the patch. It now implements 64-bit keys, 64-bit values,
and the multi-value leaves method. I've tried to remove duplicated
codes but we might find a better way to do that.

Regards,

--
Masahiko Sawada
EDB: https://www.enterprisedb.com/