PG Bug reporting form <noreply@postgresql.org> writes:
> create a table only one text/varchar colume, storage options
> toast_tuple_target doesn't work, see:
The reason your first example isn't doing anything is that the tuples are
shorter than TOAST_TUPLE_THRESHOLD, which is the threshold row length for
applying the toasting code at all. The reloption doesn't affect that;
it only changes the target length once we've gotten into the toaster.
It's not real clear to me why whoever provided a knob for
TOAST_TUPLE_TARGET didn't see fit to also provide one for
TOAST_TUPLE_THRESHOLD, but I suppose that was a deliberate choice.
The documentation is certainly clear enough that you can only
adjust the target.
regards, tom lane