Re: MERGE ... RETURNING

Jeff Davis <pgsql@j-davis.com>

From: Jeff Davis <pgsql@j-davis.com>

To: Vik Fearing <vik@postgresfriends.org>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Dean Rasheed <dean.a.rasheed@gmail.com>

Cc: Isaac Morland <isaac.morland@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2023-07-12T23:48:29Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Add RETURNING support to MERGE.
- c649fa24a42b 17.0 landed
doc: Improve a couple of places in the MERGE docs.
- 97d4262683ac 17.0 landed
- d4c573d8e81e 16.3 landed
- a875743ff402 15.7 landed
doc: improve description of privileges for MERGE and update glossary.
- 4bc8f29088f8 17.0 landed
- 3b6728910ace 16.2 landed
- ff772853d02e 15.6 landed
Fix RLS policy usage in MERGE.
- c2e08b04c9e7 17.0 cited
Fix leak of LLVM "fatal-on-oom" section counter.
- 4f4d73466d71 17.0 cited
Implement outer-level aggregates to conform to the SQL spec, with
- e649796f128b 7.4.1 cited

On Wed, 2023-07-12 at 03:47 +0200, Vik Fearing wrote:

> There is no RETURNING clause in Standard SQL, and the way they would
> do 
> this is:
> 
>      SELECT ...
>      FROM OLD TABLE (
>          MERGE ...
>      ) AS m
> 
> The rules for that for MERGE are well defined.

I only see OLD TABLE referenced as part of a trigger definition. Where
is it defined for MERGE?

In any case, as long as the SQL standard doesn't conflict, then we're
fine. And it looks unlikely to cause a conflict right now that wouldn't
also be a conflict with our existing RETURNING clause elsewhere, so I'm
not seeing a problem here.

Regards,
	Jeff Davis