hi. about this issue, last email in 2012 (https://postgr.es/m/8967.1353167...@sss.pgh.pa.us) """ Even if it happens to be trivial in the current patch, it's an added functional requirement that we might later regret having cavalierly signed up for. And, as noted upthread, relations that support only one direction of COPY don't exist at the moment; that would be adding an asymmetry that we might later regret, too.
regards, tom lane """ but now we have numerous COPY options that work solely in a single direction of COPY. I think now we can make some kind of relation (pg_class.relkind) that only works in one direction of COPY.
