SQL/JSON features for v15

Hi,

(Personal hat, not RMT hat unless otherwise noted).

This thread[1] raised some concerns around the implementation of the 
SQL/JSON features that are slated for v15, which includes an outstanding 
open item[2]. Given the current state of the discussion, when the RMT 
met on Aug 8, they several options, readable here[3]. Given we are now 
into the later part of the release cycle, we need to make some decisions 
on how to proceed with this feature given the concerns raised.

Per additional discussion on the thread, the group wanted to provide 
more visibility into the discussion to get opinions on how to proceed 
for the v15 release.

Without rehashing the thread, the options presented were:

1. Fixing the concerns addressed in the thread around the v15 SQL/JSON 
features implementation, noting that this would likely entail at least 
one more beta release and would push the GA date past our normal timeframe.

2. Try to commit a subset of the features that caused less debate. This 
was ruled out.

3. Revert the v15 SQL/JSON features work.

<RMT hat>
Based on the current release timing and the open issues presented on the 
thread, and the RMT had recommended reverting, but preferred to drive 
consensus on next steps.
</RMT hat>

 From a release advocacy standpoint, I need about 6 weeks lead time to 
put together the GA launch. We're at the point where I typically deliver 
a draft release announcement. From this, given this involves a high 
visibility feature, I would want some clarity on what option we would 
like to pursue. Once the announcement translation process has begun (and 
this is when we have consensus on the release announcement), it becomes 
more challenging to change things out.

 From a personal standpoint (restating from[3]), I would like to see 
what we could do to include support for this batch of the SQL/JSON 
features in v15. What is included looks like it closes most of the gap 
on what we've been missing syntactically since the standard was adopted, 
and the JSON_TABLE work is very convenient for converting JSON data into 
a relational format. I believe having this feature set is important for 
maintaining standards compliance, interoperability, tooling support, and 
general usability. Plus, JSON still seems to be pretty popular.

We're looking for additional input on what makes sense as a best course 
of action, given what is presented in[3].

Thanks,

Jonathan

[1] 
https://www.postgresql.org/message-id/flat/20220616233130.rparivafipt6doj3%40alap3.anarazel.de
[2] https://wiki.postgresql.org/wiki/PostgreSQL_15_Open_Items
[3] 
https://www.postgresql.org/message-id/787cef45-15de-8f1d-ed58-a1c1435bfc0e%40postgresql.org