On Mon, Jan 6, 2025 at 3:45 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > SELECT ... FROM (VALUES (...) ORDER BY a) v(a,b,c) > > If it'd been like that all along, nobody would blink at it I think, > even though you could argue that it's action-at-a-distance to let > an outer alias affect what happens inside the implicit subquery.
To be honest, that pushdown feels really uncomfortable to me. To me, the natural syntax for associating an alias with a VALUES clause would be something like "VALUES (...) myalias" or, if you also wanted column aliasing, "VALUES (...) myalias(a,b,c)". That would feel just like what we allow when aliasing a table or a function reference. But to not allow that syntax but then allow the outer alias to propagate inward in this one case seems quite strange to me. It doesn't really seem evil in a vacuum, but it seems non-orthogonal with what we do everywhere else, because aliases in SQL generally flow outward, not inward. -- Robert Haas EDB: http://www.enterprisedb.com
