Re: pg_attribute, pg_class, pg_depend grow huge in count and sizewith multiple tenants.

Hi,

On Thu, May 7, 2020 at 6:08 PM Rory Campbell-Lange <rory@campbell-lange.net> wrote:

One of our clusters has well over 500 databases fronted by pg_bouncer.

We get excellent connection "flattening" using pg_bouncer with
per-database connection spikes dealt with through a reserve pool.

What if you see at least 4 connections being established by each client during peak ? And if you serve 4 or 2  connections per each DB, then you are creating 1000 or more reserved connections with 500 DBs in a cluster. 

The nice thing about separate databases is that it is easy to scale
horizontally.

Agreed. But, how about autovacuum ? Workers shift from DB to DB and 500 clusters means you may have to have a lot of manual vacuuming in place as well.