Re: [PoC] XMLCast (SQL/XML X025)

Marcos Pegoraro <marcos@f10.com.br>

From: Marcos Pegoraro <marcos@f10.com.br>
To: Jim Jones <jim.jones@uni-muenster.de>
Cc: Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@lists.postgresql.org, Vik Fearing <vik@postgresfriends.org>
Date: 2025-11-29T11:38:58Z
Lists: pgsql-hackers
Em sex., 28 de nov. de 2025 às 17:07, Jim Jones <jim.jones@uni-muenster.de>
escreveu:

> Character data type in this sentence means the character types[1] as a
> category, not the type character or character varying.
>
Yes, I understand that, but  saying character confuses me a bit.

Interval is already part of the date/time types[1]
>
Fine.

Not really. XMLCast implements the type-specific lexical and semantic
> rules defined by SQL/XML, which apply only to base (non-domain) data
> types. Although the grammar permits a domain name as a target, the
> standard does not define any XML-specific semantics for domains.
> Supporting them would go beyond the scope of this patch, and users
> who need a domain can IMHO cast the XMLCast result afterward.
>
Correct. So maybe would be fine to explain this on SGML part, because a
domain is sometimes used just as an alias of a base type, without checking
or any other feature.