On 2020-04-20 22:36, Robert Haas wrote:
My suspicion is that it has mostly to do with adequately utilizing the hardware resources on the server side. If you are network-constrained, adding more connections won't help, unless there's something shaping the traffic which can be gamed by having multiple connections.
This is a thing. See "long fat network" and "bandwidth-delay product" (https://en.wikipedia.org/wiki/Bandwidth-delay_product). The proper way to address this is presumably with TCP parameter tuning, but in practice it's often easier to just start multiple connections, for example, when doing a backup via rsync.
-- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
