> select audit.enable_tracking('public.members');
So you can actually have functions that have side effects in a select statement? I guess nothing prevents it, so it is allowed. But somehow I have the impression that select statements don't change anything.
(DON'T ACTUALLY DO THIS on anything other than a personal test db as it will kill all the connections it has permission to kill)
Related, postgres has a number of different volatility options for functions so you can declare if there are side effects: https://www.postgresql.org/docs/14/xfunc-volatility.html These can become very important in some cases to let the optimizer have the freedom to shine.
I think you can use a standalone VALUES statement to avoid side effects? Those aren't well supported even though it's part of the SQL spec, but postgres does have them.