Thanks for your post, but it's too general. Maybe it's my fault I wasn't too specific with my question. So, I'm trying to be more precise
I got two schema.yml files. One with my tables, and the second with plugin tables schema. And now: if my tables have some key relations to tables in plugin schema, then should I leave both schemas just like they exists, or maybe should I join them into one schema file, or ...?
At the moment I got two schemas, but I see after "build-all-reload" tables in MySQL are created without key relations - so this is rather wrong...
And one more important thing. The ORDER of creating model and sql for schemas. I guess the first one is schema from main config folder, then schema from plugin. Am I correct? If so, then how to use sfGuardUser to make it fully functional in frontend application?