Pavel Stehule <pavel.stehule@gmail.com> writes:
> in 99.99% the second argument will be a constant. Can we use this
> information and optimize function for this case?
> The detoast on every row can take some percent from a performance.
What detoast? There won't be one for a constant, nor even for a
variable in any sane situation --- who's going to be using
multi-kilobyte delimiter values? And if they do, aren't they likely
to run out of memory for the result long before the repeated detoasts
become an interesting problem? You're arguing about a case that
seems quite irrelevant to the real world.
regards, tom lane
