How to Manage Connections Efficiently in Postgres, or Any Database
note that while the MySQL connection-pool equation is pretty different from that of Postgresql's, at least in my experience MySQL connections use less memory (sorry, no measurements handy, feel free to correct me, but they generally are handled as a thread rather than an entire subprocess and we regularly see apps that spin up thousands of them fairly cheaply) and also have a lower startup time (also anecdotal, sorry), the MySQL world does finally have middleware connection pools now such as proxysql: https://proxysql.com/