Gregory Stark <stark@enterprisedb.com> writes:
> Is there a null configuration which could be the default for the casts?
If we did that then there would be no point in having a GUC variable,
because it wouldn't control anything.
While that is certainly an alternative solution, I think it's riskier
than having the GUC variable and just preventing (or at least
discouraging) people from relying on it in their index definitions.
The problem is that people will resort to "ALTER CONFIGURATION default"
to tune their setups, and anytime you make a nontrivial change that way,
you run the risk of breaking your existing indexes.
regards, tom lane