On Mon, Mar 12, 2018 at 2:19 PM, P O'Toole <P.OToole@uwyo.edu> wrote:
According to the System Information Functions docs, pg_get_function_identity_arguments(OID) should simply "get argument list to identify a function (without default values)", but one example of how it behaves strangely is that:
FWIW a simple \dfS percentile* will elicit the same description.
I suppose it depends on what you are using the output for - the (percentile*) functions that are decorated with ORDER BY are exclusively aggregate, as opposed to standard, functions.
An ORDER BY is not a "default value" so we aren't really contradicting the docs - though seeing ORDER BY in a function signature is a surprise to me too...but reading the doc for CREATE AGGREGATE the SQL command syntax is:
ORDER BY [ argmode ] [ argname ] arg_data_type [ , ... ] )
So I'd have to say this is working correctly.
I seem to recall some recent (last few weeks) discussion regarding aggregates vs functions in the information schema. That may prove to be enlightening but at the moment I don't have time to go look for and review it.