While reading about deprecating and removing various things in other threads, I was wondering about how deprecated SELECT INTO is. There are various source code comments about this, but the SELECT INTO reference page only contains soft language like "recommended". I'm proposing the attached patch to stick a more explicit deprecation notice right at the top.
I also found some gratuitous uses of SELECT INTO in various tests and documentation (not ecpg or plpgsql of course). Here is a patch to adjust those to CREATE TABLE AS.
I don't have a specific plan for removing top-level SELECT INTO altogether, but there is a nontrivial amount of code for handling it, so there would be some gain if it could be removed eventually.