If you're using ``hibernate.connection.driver_class`` and ``hibernate.connection.url``, you don't need ``hibernate.hikari.dataSourceClassName``.  When using a DriverManager setup, HikariCP is going to wrap the use of DriverManager in an internal class called ``DriverDataSource`` automatically.  You are still free to use ``hibernate.hikari.dataSource.*`` to configure properties that will be passed into the ``Driver.getConnection(url, properties)`` call.

Most performant would be not using a DriverManager-based setup, and instead using a pure DataSource approach, in which case the ``hibernate.connection`` properties are not needed except for ``hibernate.connection.provider_class``.  Everything else can be configured though ``hibernate.hikari.*`` properties, for example:
```ini
hibernate.dialect=org.hibernate.dialect.H2Dialect
hibernate.jdbc.batch_size=10
hibernate.connection.provider_class=HikariCPConnectionProvider

hibernate.hikari.dataSourceClassName=org.h2.jdbcx.JdbcDataSource
hibernate.hikari.dataSource.user=sa
hibernate.hikari.dataSource.url=jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1;MVCC=TRUE
```