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

On Tue, Jan 16, 2024 at 1:18 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> Just changing "items" to be the local tidstore struct could make the
> code tricky a bit, since max_bytes and num_items are on the shared
> memory while "items" is a local pointer to the shared tidstore.

Thanks for trying it this way! I like the overall simplification but
this aspect is not great.
Hmm, I wonder if that's a side-effect of the "create" functions doing
their own allocations and returning a pointer. Would it be less tricky
if the structs were declared where we need them and passed to "init"
functions?

That may be a good idea for other reasons. It's awkward that the
create function is declared like this:

#ifdef RT_SHMEM
RT_SCOPE RT_RADIX_TREE *RT_CREATE(MemoryContext ctx, Size max_bytes,
dsa_area *dsa,
int tranche_id);
#else
RT_SCOPE RT_RADIX_TREE *RT_CREATE(MemoryContext ctx, Size max_bytes);
#endif

An init function wouldn't need these parameters: it could look at the
passed struct to know what to do.