[majodev]

I'm generally not a fan of emulating database behavior through a mocking layer while testing/implementing. Even minor version changes of PostgreSQL plus it's extensions (e.g. PostGIS) may introduce slight differences, e.g. how indices are used, function deprecations, query planner, etc. . It might not even be an erroneous result, just performance regressions or slight sorting differences in the returned query result.

We try to approximate local/test and live as close as possible, therefore using the same database, with the same extensions in their exact same version is a hard requirement for us while implementing/testing locally.

However, I have no experience with H2 (and the modern Java ecosystem in general), so cannot talk about how close their emulation implementation resembles PostgreSQL behavior.