Performance cancancan

with left joins

Warming up --------------------------------------
                easy   860.000  i/100ms
              cannot   621.000  i/100ms
       simple filter   596.000  i/100ms
            one join   260.000  i/100ms
           two joins   207.000  i/100ms
         three joins   163.000  i/100ms
Calculating -------------------------------------
                easy      8.739k (± 4.8%) i/s -     43.860k in   5.031055s
              cannot      6.233k (± 5.2%) i/s -     31.671k in   5.096447s
       simple filter      6.303k (± 6.2%) i/s -     31.588k in   5.032223s
            one join      2.685k (± 7.9%) i/s -     13.520k in   5.071367s
           two joins      2.058k (± 5.6%) i/s -     10.350k in   5.045809s
         three joins      1.633k (± 6.9%) i/s -      8.150k in   5.019697s

with union

Warming up --------------------------------------
                easy   747.000  i/100ms
              cannot   769.000  i/100ms
       simple filter   557.000  i/100ms
            one join   139.000  i/100ms
           two joins    98.000  i/100ms
         three joins    61.000  i/100ms
Calculating -------------------------------------
                easy      7.252k (±14.6%) i/s -     35.109k in   5.007959s
              cannot      7.292k (±14.3%) i/s -     36.143k in   5.122395s
       simple filter      5.264k (±16.3%) i/s -     25.622k in   5.070840s
            one join      1.526k (±16.9%) i/s -      7.367k in   5.077286s
           two joins    875.786  (±18.5%) i/s -      4.214k in   5.063460s
         three joins    665.391  (±12.8%) i/s -      3.294k in   5.067162s