If I set a custom GUC variable to a boolean value, such as:
SET myapp.audit = 'on';
is there a way to test it for truthiness in the same way the standard
built-in variables are? IOW, the docs say a boolean can be written as:
Boolean values can be written as on, off, true, false, yes, no, 1, 0 (all
case-insensitive) or any unambiguous prefix of these.