On Wed, 20 Feb 2019 at 10:49, Tom Lane <t...@sss.pgh.pa.us> wrote: > What if we dropped that idea, and instead defined the plan tree as > returning only the columns that are updated by SET, plus the row > identity? It would then be the ModifyTable node's job to fetch the > original tuple using the row identity (which it must do anyway) and > form the new tuple by combining the updated columns from the plan > output with the non-updated columns from the original tuple. > > DELETE would be even simpler, since it only needs the row identity > and nothing else.
While I didn't look at the patch in great detail, I think this is how Pavan must have made MERGE work for partitioned targets. I recall seeing the tableoid being added to the target list and a lookup of the ResultRelInfo by tableoid. Maybe Pavan can provide more useful details than I can. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
