On 10.01.26 07:16, Paul A Jungwirth wrote:
> We would need to document these columns.
Done that.
> The C code uses `mltrng` a lot. Do we want to use that here? I don't
> see it in the catalog yet, but it seems clearer than `rngm`. I guess
> we have to start with `rng` though. We have `rngmultitypid`, so maybe
> `rngmulticonstr0`? Okay I understand why you went with `rngm`.
I tuned the naming again in the new patch. I changed "constr" to
"construct" because "constr" read too much like "constraint" to me. I
also did a bit of "mtlrng". I think it's a bit more consistent and less
ambiguous now.
> It's tempting to use two oidvectors, one for range constructors and
> another for multirange, with the 0-arg constructor in position 0,
> 1-arg in position 1, etc. We could use InvalidOid to say there is no
> such constructor. So we would have rngconstr of `{0,0,123,456}` and
> mltrngconstr of `{123,456,789}`. But is it better to avoid varlena
> columns if we can?
I don't think oidvectors would be appropriate here. These are for when
you have a group of values that you need together, like for function
arguments. But here we want to access them separately. And it would
create a lot of notational and a bit of storage overhead.
I had in the previous patch used some arrays as arguments in the
internal functions, but in the second patch I'm also getting rid of that
because it's uselessly inconsistent.
> ```
> diff --git a/src/include/catalog/pg_range.h b/src/include/catalog/pg_range.h
> index 5b4f4615905..ad4d1e9187f 100644
> --- a/src/include/catalog/pg_range.h
> +++ b/src/include/catalog/pg_range.h
> @@ -43,6 +43,15 @@ CATALOG(pg_range,3541,RangeRelationId)
> /* subtype's btree opclass */
> Oid rngsubopc BKI_LOOKUP(pg_opclass);
>
> + /* range constructor functions */
> + regproc rngconstr2 BKI_LOOKUP(pg_proc);
> + regproc rngconstr3 BKI_LOOKUP(pg_proc);
> +
> + /* multirange constructor functions */
> + regproc rngmconstr0 BKI_LOOKUP(pg_proc);
> + regproc rngmconstr1 BKI_LOOKUP(pg_proc);
> + regproc rngmconstr2 BKI_LOOKUP(pg_proc);
> +
> /* canonicalize range, or 0 */
> regproc rngcanonical BKI_LOOKUP_OPT(pg_proc);
> ```
>
> Is there a reason you're adding them in the middle of the struct? It
> doesn't help with packing.
Well, initially I had done that so that the edits to pg_range.dat are
easier. But I think this order makes some sense, because it has the
mandatory data first and then the optional data later. But it doesn't
matter much either way.
> This needs some kind of pg_upgrade support I assume? It will have to
> work for user-defined rangetypes too.
No, I don't think there needs to be pg_upgrade support. Existing range
types are dumped as CREATE TYPE ... RANGE commands, and when those get
restored it will create the new catalog entries.
