Does pgbouncer offer an advantage to a Hikari Pool?

[Henri Cook]

Hi everyone,

I run a medium sized commercial JDBC app with a Hikari connection pool on each instance.

We often muse about the potential benefits of putting a pgbouncer instance between our postgres database and the app. People on our team have had experience of pgbouncer in *transaction mode* being particularly great because it simulates more connections than you actually have available and uses hand wavey magic in the background to only really use a limited number of connections to the database proper.

My question is: Would it offer much of a benefit when we already have Hikari? As I see it Hikari uses the number of real connections to the database but crucially queues other requests until a connection is available - is this basically the same thing as what pgbouncer in transaction mode is doing? Assuming of course that our app releases each connection after each transaction is complete (it does AFAIK).

Best Regards,

Henri