[mgamer]

I use MySQL in my system but the advice should be applicable to Postgres as well: keep your test database in a ramdisk. By moving my MySQL to ramdisk I got almost a tenfold improvement when running tests on a build server. Not so much (but also significant) improvement when running tests on my development machine.

[jeltz]

We have benchmarked this at our company and notivced that using a ramdisk does not give much extra performance over just turning of synchronous_commit in PostgreSQL. Most of the slowdown from the database turned out to be latency from waiting on the background writer to fsync.

[jackweirdy]

Why do you think there was a difference between tests on a build server and on your development machine? Was it just a case of the build server being configured for performance?

[mgamer]

I'm pretty sure that it's down to hard disk performance. I don't recall exact numbers but difference in IOPS between my development machine and a build server in the cloud (Azure) was greatly in favour of the former.