Feature request: DEFAULT as input value of function argument

Hi, community

The case:

E.g. I need to write a function that should do updates of a table. In
the function I have to specify necessary columns I need to update as
arguments and write update of the columns with this arguments.
Everything is ok but the case when I need to skip some column in
update to use DEFAULT value of the column.

IMHO convenient solution is to make possible to specify something like
COLUMN_DEFAULT as input value of function.

I wonder if it's possible.

--
Regards,
Sergey Konoplev
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