Обсуждение: JSON type unsupported

On 9/26/23 11:33, Erki Eessaar wrote:
> Hello
> 
> According to Appendix D. SQL Conformance
> 
> https://www.postgresql.org/docs/current/unsupported-features-sql-standard.html
> 
> the feature T801 JSON data type is unsupported. However, PostgreSQL has data types JSON and JSONB. Here
(http://peter.eisentraut.org/blog/2023/04/18/postgresql-and-sql-2023)it is also said that T801 is supported.
 
> 
> Perhaps there are some technical details that I am not aware of. However, I wanted to point this out.

Thank you for pointing this out.  Peter's blog is slightly misleading in 
that we do have the JSON data type, but the T801 feature is far from 
complete.

For example, we do not have the JSON_SERIALIZE(), JSON()[1], 
JSON_SCALAR() functions.  We don't have the IS JSON predicate, or a few 
other things hiding behind T801.

All in all, I would not say we support the JSON data type the way the 
standard intends, and therefore we should not claim to support T801.


[1] This is a fully specified parsing function, not just a cast like we 
have today.
-- 
Vik Fearing

Vik Fearing <vik@postgresfriends.org> writes:
> Thank you for pointing this out.  Peter's blog is slightly misleading in 
> that we do have the JSON data type, but the T801 feature is far from 
> complete.

> For example, we do not have the JSON_SERIALIZE(), JSON()[1], 
> JSON_SCALAR() functions.  We don't have the IS JSON predicate, or a few 
> other things hiding behind T801.

> All in all, I would not say we support the JSON data type the way the 
> standard intends, and therefore we should not claim to support T801.

Agreed, but should we say "partial support", as we do for some other
feature identifiers?

            regards, tom lane

On 26.09.23 17:31, Vik Fearing wrote:
> For example, we do not have the JSON_SERIALIZE(), JSON()[1], 
> JSON_SCALAR() functions.  We don't have the IS JSON predicate, or a few 
> other things hiding behind T801.

AFAICT, commit 03734a7fed, which is new in master, adds exactly those, 
so maybe we could toggle this feature to supported?

On 10/6/23 11:57, Peter Eisentraut wrote:
> On 26.09.23 17:31, Vik Fearing wrote:
>> For example, we do not have the JSON_SERIALIZE(), JSON()[1], 
>> JSON_SCALAR() functions.  We don't have the IS JSON predicate, or a 
>> few other things hiding behind T801.
> 
> AFAICT, commit 03734a7fed, which is new in master, adds exactly those, 
> so maybe we could toggle this feature to supported?

That is better than before, but even those functions are not complete. 
I am okay with flipping to supported but with a note saying there are 
many subfeatures missing.
-- 
Vik Fearing