IT Hare: Ultimate DB Heresy: Single Modifying DB Connection. Part I. Performanc - http://highscalability.com/blog/2016/11/22/it-hare-ultimate-db-heresy-single-modifying-db-connection-pa.html

How yandex.metrica improve DB reading - http://highscalability.com/blog/2017/9/18/evolution-of-data-structures-in-yandexmetrica.html