Best Practices

Let's also add a data point to this.

When we recently had to migrate projects to the new details we processed a per update that serialized each project in his own DJ. This is how much time was spent just serializing projects:

```
p = Project.first

puts Benchmark.measure { 23718.times { p.to_yaml } }
=>  24.740000   0.040000  24.780000 ( 24.845375)

puts Benchmark.measure { 23718.times { p.id.to_yaml } }
=>  1.120000   0.040000   1.160000 (  1.165733)
```

In parenthesis the number of seconds spent.