In theory, a database that uses immutable data structures (the hash array mapped trie popularized by Clojure) could allow instant clones on any filesystem, not just ZFS/XFS, and allow instant clones of any subset of the data, not just the entire db. I say "in theory" but I actually built this already so it's not just a theory. I never understood why there aren't more HAMT based databases.
For anyone looking for a simple GUI for local testing/development of Postgres based applications. I built a tool a few years ago that simplifies the process: https://github.com/BenjaminFaal/pgtt
We do this, preview deploys, and migration dry runs using Neon Postgres’s branching functionality - seems one benefit of that vs this is that it works even with active connections which is good for doing these things on live databases.
OP here - yes, this is my use case too: integration and regression testing, as well as providing learning environments. It makes working with larger datasets a breeze.
OP here - still have to try (generally operate on VM/bare metal level); but my understanding is that ioctl call would get passed to the underlying volume; i.e. you would have to mount volume
Also docker link seems to be broken.