You don't have to trust me, here is a diff you can apply of the work I did:
https://gist.github.com/spion/2779ae6dc9552c229c1eeacd90c03b...you can run ./tfb --test express-postgres and compare.
If you can't wait for all the tests to complete, a representative one can be obtained more quickly by running
./tfb --test express-postgres --type db --query-levels 10 --concurrency-levels 128
