Hi, On 2019-11-12 17:39:20 -0500, Tom Lane wrote: > > and under what other > > circumstances one would only encounter 'cleaned up' TupleDescs with > > no dropped attributes, and contiguous numbers for the real ones? > > I don't believe we ever include dropped columns in a projection result, > so generally speaking, the output of a query plan node wouldn't have them. > > There's a semi-exception, which is that the planner might decide that we > can skip a projection step for the output of a table scan node, in which > case dropped columns would be included in its output. But that would only > be true if there are upper plan nodes that are doing some projections of > their own. The final query output will definitely not have them.
I *think* we don't even do that, because build_physical_tlist() bails out if there's a dropped (or missing) column. Or are you thinking of something else? Greetings, Andres Freund
