One challenge with running PostgreSQL in production on Kubernetes is that it does not behave nicely under high memory pressure. PostgreSQL likes to get NULL back from malloc such that it can gracefully abort transactions (overcommit_memory = 2 in Linux). However, this model of tracking and dealing with memory pressure is still not available at the cgroup level. Instead, processes will be OOM killed. In PostgreSQL, that triggers potentially lengthy crash recovery and therefore downtime. On the flip side, the cost of deploying a hot standby is often lower on Kubernetes, but failing over due to high memory pressure can also lead to pathological behaviour.

A good discussion of this issue by Joe Conway: https://www.crunchydata.com/blog/deep-postgresql-thoughts-th...

Hence, not completely the same as running on a VM.