On 04/15/2011 05:36 PM, Tom Lane wrote:
> Basil Bourque<basil(dot)list(at)me(dot)com> writes:
>> When a trigger calls a function, that function can determine if it is being called from within a trigger by testing for a value in the special variable "TG_OP".
>
> Uh, no, not really. TG_OP is a local variable in the trigger function;
> it's not visible from elsewhere.
>
>> But what if a trigger calls a function that calls a 2nd function via the "PERFORM" command? Can that 2nd function tell if it is being run in a trigger?
>
> No. Doesn't really matter whether you use PERFORM or not.
>
> regards, tom lane
>
One could pass a boolean from function A to B, I suppose.