PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> There are simple case when type coercion work with common btree index but
> doesn't work with btree_gin.
btree_gin doesn't bother to cover any cross-type operators.
That could possibly be fixed, but I think it'd be a pain
since the applicable cross-type operators would vary for
each data type btree_gin covers.
regards, tom lane