On Thu, Oct 2, 2014 at 1:10 PM, Bruce Momjian <br...@momjian.us> wrote: > I think if we use the MERGE command for this feature we would need to > use a non-standard keyword to specify that we want OLTP/UPSERT > functionality. That would allow us to mostly use the MERGE standard > syntax without having surprises about non-standard behavior. I am > thinking of how CONCURRENTLY changes the behavior of some commands.
That would leave you without a real general syntax. It'd also make having certain aspects of an UPSERT more explicit be a harder goal (there is no conventional join involved here - everything goes through a unique index). Adding the magic keyword would break certain other parts of the statement, so you'd have exact rules for what worked where. I see no advantage, and considerable disadvantages. Note that I've documented a lot of this stuff here: https://wiki.postgresql.org/wiki/UPSERT Mapping the join thing onto which unique index you want to make the UPSERT target is very messy. There are a lot of corner cases. It's quite ticklish. Please add to it if you think we've missed something. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
