[ddebernardy]

Yeah. Technically, `foo varchar(n)` amounts to syntactic sugar for `foo varchar check(length(foo) <= n)`.

What the benchmarks show, if anything, is that while the `check` involves negligible overhead per row, the overhead can eventually be enough to make a measurable difference.

Not to mention, the Postgres actually manual says as much as the above, in its description of text types.