dawk i=16 join
131071

real	0m0.020s
user	0m0.016s
sys	0m0.003s

dawk i=16 xjoin
131071

real	0m0.045s
user	0m0.045s
sys	0m0.000s

dawk i=18 join
524287

real	0m0.068s
user	0m0.054s
sys	0m0.013s

dawk i=18 xjoin
524287

real	0m0.161s
user	0m0.147s
sys	0m0.013s

dawk i=20 join
2097151

real	0m0.262s
user	0m0.241s
sys	0m0.021s

dawk i=20 xjoin
2097151

real	0m0.472s
user	0m0.440s
sys	0m0.030s

dawk i=22 join
8388607

real	0m0.763s
user	0m0.711s
sys	0m0.050s

dawk i=22 xjoin
8388607

real	0m1.941s
user	0m1.855s
sys	0m0.080s