Re: INFORMATION_SCHEMA.routine_column_usage

> Here
> https://www.postgresql.org/docs/current/infoschema-routine-column-usage.html <https://www.postgresql.org/docs/current/infoschema-routine-column-usage.html>
> 
> it is stated that "The view |routine_column_usage| is meant to identify 
> all columns that are used by a function or procedure. This information 
> is currently not tracked by PostgreSQL."
> 
> However, this claim is incorrect because the view provides information 
> about the column usage of SQL functions that have SQL-standard function 
> body.

Correct, the documentation was not updated when this was added.  A few 
other views are similarly affected.  How about this attached patch.