It depends on how knex is used. If it gives you a method to run a DB query, and internally checks out a connection, runs the query and releases the connection,

It depends on how knex is used. If it gives you a method to run a DB query, and internally checks out a connection, runs the query and releases the connection, then it’s already doing exactly what would happen with a proxy. If it or you are setting up middleware to start a transaction before every request, or put a checked out connection in the request context, that’s a lot of possible inefficiency. If you really want the convenience this offers, and have request flows that do a lot of other non-DB work, you’ll need a pooling proxy. If your request handling is very database heavy and does nothing else, then automatic request level connection check out is still efficient, even without a proxy. Even if you have a proxy one real connection is going to be working the entire duration of the request anyway.