I'm having a really hard time refraining from writing a really snarky "Switch to MySQL" type response, not because I think that MySQL outperforms PostgreSQL, but because there is always somebody on every MySQL article discussion who does this. Ok, that's off my chest, sorry to rant.

I enjoyed this video, even though I'm not a PostgreSQL guy, as it has a lot of good generic info. The advice about XFS and noatime was right on the money, although I don't think he strongly stated enough why you don't want to run EBS volumes over software RAID-0. In my experience this is a really bad idea, because just one of those EBS volumes getting picking up a laggy await (happens pretty frequently with volumes I've seen in the wild) will drag down the performance of the entire array. Also I'm told that the old "RAID-5 is always bad" notion is considerably more nuanced nowadays, and that many of the earlier OLTP write performance problems with RAID-5 have been largely mitigated with modern RAID controllers.