Rails counter cache and associations

Date: 20-June-2017 Symptom: Extremely fast benchmarking in tests Cause: Good question, something broken in the guts of ActiveRecord and not backported How found: After messing around a lot, added a column of name association_count and then was able to reproduce the error. Fix: Still working on that part. Time taken to resolve bug: 4 hours. Lessons: Make damn sure when you're doing a benchmark that you're actually getting the expected output.