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

On Tue, Dec 27, 2022 at 2:24 PM John Naylor
<john(dot)naylor(at)enterprisedb(dot)com> wrote:
>
> On Tue, Dec 27, 2022 at 12:14 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > On Fri, Dec 23, 2022 at 8:47 PM John Naylor
> > <john(dot)naylor(at)enterprisedb(dot)com> wrote:
>
> > These 4 patches make sense to me.We can merge them into 0002 patch
>
> Okay, then I'll squash them when I post my next patch.
>
> > and I'll do similar changes for functions for leaf nodes as well.
>
> I assume you meant something else? -- some of the differences between inner and leaf are already abstracted away.

Right. If we template these routines I don't need that.

>
> In any case, some things are still half-baked, so please wait until my next patch before doing work on these files.
>
> Also, CI found a bug on 32-bit -- I know what I missed and will fix next week.

Thanks!

>
> > > 0010 and 0011 template a common implementation for both leaf and inner nodes for searching and inserting.
> > >
> > > 0012: While at it, I couldn't resist using this technique to separate out delete from search, which makes sense and might give a small performance boost (at least on less capable hardware). I haven't got to the iteration functions, but they should be straightforward.
>
> Two things came to mind since I posted this, which I'll make clear next patch:
> - A good compiler will get rid of branches when inlining, so maybe no difference in code generation, but it still looks nicer this way.
> - Delete should really use its own template, because it only _accidentally_ looks like search because we don't yet shrink nodes.

Okay.

>
> > What do you
> > think about how we can expand this template method to deal with DSA
> > memory? I imagined that we load say radixtree_template.h with some
> > macros to use the radix tree like we do for simplehash.h. And
> > radixtree_template.h further loads xxx_impl.h files for some internal
> > functions.
>
> Right, I was thinking the same. I wanted to start small and look for opportunities to shrink the code footprint.

Thank you for your confirmation!

Regards,

--
Masahiko Sawada
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