We have https://github.com/ezsystems/ezpublish-kernel/blob/master/data/mysql/schema.sql but no corresponding Postgres schema file - this should be added.
Perhaps we can use https://github.com/ezsystems/ezpublish-kernel/blob/master/eZ/Publish/Core/Persistence/Legacy/Tests/_fixtures/schema.pgsql.sql as a source?

As a result of many discussions and reviews of the prototype we decided to make this a part of 2.0 release and use Doctrine Schema files.
After some investigation we've found out that there's no official schema file format as Doctrine DBAL Schema Tool is PHP API. (Not to be confused with Doctrine ORM which actually has defined Yaml format).
We've decided to create our own Yaml format of a schema which uses Doctrine Schema Tool.

The remaining thing to do is to make installer an API, so developers can call it from their own code without a need to call ezplatform:install command. However, of course the command will work as it worked before - there's no reason for BC break on that.

The major BC break is related to replacing schema.sql with schema.yml file. It's important to make it extensible as developers tend to modify it for custom needs. This can be achieved by creating some schema file provider. TBD.