On Fri, Mar 23, 2018 at 6:45 AM, Peter Geoghegan <p...@bowt.ie> wrote:
> On Thu, Mar 22, 2018 at 6:02 PM, Alvaro Herrera <alvhe...@alvh.no-ip.org> > wrote: > > Incremental development is a good thing. Trying to do everything in a > > single commit is great when time is infinite or even merely very long, > > but if you run out of it, which I'm sure is common, leaving some things > > out that can be reasonable implemented in a separate patch is perfectly > > acceptable. > > We're talking about something that took me less than an hour to get > working. AFAICT, it's just a matter of tweaking the grammar, and > adding a bit of transformWithClause() boilerplate to the start of > transformMergeStmt(). >> >> >> I quickly implemented CTE support myself (not wCTE support, since >> MERGE doesn't use RETURNING), and it wasn't tricky. It seems to work >> when I mechanically duplicate the approach taken with other types of >> DML statement in the parser. I have written a few tests, and so far it >> holds up. >> > > Ok, thanks. I started doing something similar, but great if you have > already implemented. I will focus on other things for now. > > I am sorry. I was under the impression that you're actually writing this piece of code and hence did not pay much attention till now. I should have confirmed with you instead of assuming. I think it's a bit too late now, but I will give it a fair try tomorrow. I don't want to spend too much time on it though given how close we are to the deadline. As Alvaro said, we can always revisit this for pg12. > As I've pointed out on this thread already, I'm often concerned about > supporting functionality like this because it increases my overall > confidence in the design. If it was genuinely hard to add WITH clause > support, then that would probably tell us something about the overall > design that likely creates problems elsewhere. It's easy to say that > it isn't worth holding the patch up for WITH clause support, because > that's true, but it's also beside the point. > Understood. Thanks, Pavan -- Pavan Deolasee http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
