No, there is no embedded PostgreSQL, in the sense of an in-process-loadable database-as-a-library. PostgreSQL is process oriented; each backend has one thread, and it spawns multiple processes to do work. It doesn' make sense as a library.
The H2 database supports a limited subset of the PostgreSQL SQL dialect and the use of the PgJDBC driver.
What you can do is initdb
a new temporary database, start it with pg_ctl
on a randomized port so it doesn't conflict with other instances, run your tests, then use pg_ctl
to stop it and finally delete the temporary database.
I strongly recommend that you run the temporary postgres on a non-default port so you don't risk colliding with any locally installed PostgreSQL on the machine running the tests.
(There is "embedded PostgreSQL in the sense of ecpg, essentially a PostgreSQL client embedded in C source code as preprocessor based C language extensions. It still requires a running server and it's a bit nasty to use, not really recommended. It mostly exists to make porting from various other databases easier.)