>>>>> "Alastair" == Alastair McKinley <a.mckinley@xxxxxxxxxxxxxxxxxxxx> writes: Alastair> Hi all, Alastair> I noticed this strange behaviour whilst trying to write a Alastair> function for Postgres 11.5 (PostgreSQL 11.5 on Alastair> x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 Alastair> (Red Hat 4.8.5-36), 64-bit) and reduced it to this minimal Alastair> example. Using a function parameter in the window frame Alastair> definition seems to be the cause of the error. [...] Alastair> This appears to be a bug to me. Yes, it's a bug, related to function inlining (the select f(3); is not inlined and therefore works, but the select * from f(3); is being inlined, but the original Param is somehow making it into the final plan rather than being substituted with its value). Looking into why. -- Andrew (irc:RhodiumToad)