[takeda]

The reason for low connection limit is because every connection is a separate process. There are also various structures in postgres that are frequently traversed during various operations that large number of connections affect[1]. In my company we use aurora which supposedly was also modified connection handling to use threads to handle more connections. By default I think aurora is set to 500 connections.

In our case we had about ~200 connections to database. After we placed pgbouncer in front and reduced number of connections to 60. Our commit throughput doubled.

[1] https://brandur.org/postgres-connections