[petergeoghegan]

I would say that that's pretty dubious claim with modern versions of Postgres and MySQL/InnoDB, running on modern hardware. See for example this recent comparative Benchmark from Mark Callaghan, a well known member of the MySQL community:

https://smalldatum.blogspot.com/2021/01/sysbench-postgres-vs...

I'm not claiming that this benchmark justifies the claim that Postgres broadly performs better than MySQL/InnoDB these days -- that would be highly simplistic. Just as it would be simplistic to claim that MySQL is clearly well ahead with OLTP stuff in some kind of broad and entrenched way. It's highly dependent on workload.

Note that Postgres really comes out ahead on a test called "update-index", which involves updates that modify indexed columns -- the write amplification is much worse on MySQL there. This is precisely the opposite of what most commentators would have predicted. Including (and perhaps even especially) Postgres community people.