https://www.slashroot.in/linux-system-io-monitoring http://tatiyants.com/pev/#/plans explain for Postgres https://pgtune.leopard.in.ua/ generate postgresql.conf https://medium.com/braintree-product-technology/postgresql-at-scale-database-schema-changes-without-downtime-20d3749ed680 https://blog.storagecraft.com/raid-performance/ https://portavita.github.io/2019-07-19-PostgreSQL_effective_io_concurrency_benchmarked/