I have created a postgresql_test database/user on the postgresql-growthbook database so that @mpopov can start testing Growthbook itself. However the generation of such synthetic data requires a python environment with psycopg2, sqlalchemy or ADBC (Arrow Database Connector), along with polars. This is probably best suited for a jupyter environment, which would require access to the PG cluster from outside the Kubernetes cluster itself.
For this to work, we'd need to make ingress work for our CloudnativePG clusters, which would be a nice feature to have! Let's see whether we can make it work in a non-encrypted fashion.

