Hi, > > > I'll try to explain my motivation. Please, check it and correct me if I > > am > > > wrong. I don't keep on my implementation - just try to implement XMLTABLE > > > be consistent with another behave and be used all time without any > > > surprise. > > > > > > 1. Any function that produces a content can be used in target list. We > > > support SRF in target list and in FROM part. Why XMLTABLE should be a > > > exception? > > > > targetlist SRFs were a big mistake. They cause a fair number of problems > > code-wise. They permeated for a long while into bits of both planner and > > executor, where they really shouldn't belong. Even after the recent > > changes there's a fair amount of uglyness associated with them. We > > can't remove tSRFs for backward compatibility reasons, but that's not > > true for XMLTABLE > > > > > > > ok > > I afraid when I cannot to reuse a SRF infrastructure, I have to reimplement > it partially :( - mainly for usage in "ROWS FROM ()"
The TableExpr implementation is based on SRF now. You and Alvaro propose independent implementation like generic executor node. I am sceptic so FunctionScan supports reading from generic executor node.