Re: [HACKERS] MERGE SQL Statement for PG11

On Thu, Mar 22, 2018 at 1:06 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> I'm now proposing that I move to commit this, following my own final
> review, on Tues 27 Mar in 5 days time, giving time for cleanup of
> related issues.
>
> If there are any items you believe are still open, please say so now
> or mention any other objections you have.

I would like to see clarity on the use of multiple RTEs for the target
table by MERGE. See my remarks to Pavan just now. Also, I think that
the related issue of how partitioning was implemented needs to get a
lot more review (partitioning is the whole reason for using multiple
RTEs, last I checked). It would be easy enough to fix the multiple
RTEs issue if partitioning wasn't a factor. I didn't manage to do much
review of partitioning at all. I don't really understand how the patch
implements partitioning. Input from a subject matter expert might help
matters quite a lot.

Pavan hasn't added support for referencing CTEs, which other database
systems with MERGE have. I think that it ought to be quite doable. It
didn't take me long to get it working myself, but there wasn't follow
through on that (I could have posted the patch, which looked exactly
as you'd expect it to look). I think that we should add support for
CTEs now, as I see no reason for the omission.

In general, I still think that this patch could do with more review,
but I'm running out of time. If you want to commit it, I will not
explicitly try to block it, but I do have misgivings about your
timeframe.

-- 
Peter Geoghegan