2013/11/6 Albe Laurenz <laurenz.a...@wien.gv.at>: > I have a question concerning the Foreign Data Wrapper API: > > I find no mention of this in the documentation, but I remember that > you can only add a resjunk column that matches an existing attribute > of the foreign table and not one with an arbitrary name or > definition. > > Ist that right?
My understanding (having recently had a crack at getting an FDW working) is that the name can be arbitrary within reason - at least that's what I get from this bit of the documentation: > To do that, add TargetEntry items to parsetree->targetList, containing > expressions for the extra values to be fetched. Each such entry must > be marked resjunk = true, and > must have a distinct resname that will > identify it at execution time. Avoid using names matching ctidN or > wholerowN, as the core system can generate junk columns of these names. http://www.postgresql.org/docs/9.3/interactive/fdw-callbacks.html#FDW-CALLBACKS-UPDATE Someone more knowledgeable than myself will know better, I hope. Regards Ian Barwick -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
