>>>>> "Tom" == Tom Lane <t...@sss.pgh.pa.us> writes:
Tom> We can't inline wCTEs (those containing insert/update/delete) Tom> without risk of semantics change. Clearly. Tom> I'd also not favor changing the semantics for CTEs that are read Tom> more than once by the parent query. This one's more debatable. There will still be cases where a CTE referenced multiple times will be better inlined. (It's obviously trivial to make the posted code do it that way, just by checking cterefcount.) Tom> However, a singly-referenced SELECT CTE could reasonably be Tom> treated as equivalent to a sub-select-in-FROM, In the PoC code I also excluded SELECT FOR UPDATE from inlining. (There's already a difference between how SELECT FOR UPDATE works for CTEs compared to subqueries and views, the comments mention it) There might also be some merit in checking for volatility? -- Andrew (irc:RhodiumToad)
