The Data Sync UI should use Postgres to store all it's data. The first will be the data sources. We also want to use sequelize (http://docs.sequelizejs.com/) to have an abstraction over pure Postgres and SQL. Server and Backend need to use the same schema (Sequelize lets you define the schema in Javascript). Have a look at the sync server for this: https://github.com/aerogear/data-sync-server/pull/9

At some point UI and sync server will use the same database. But for development we should sync the schema when the UI starts (let sequelize create the tables if they dont exist). We can also run a script to create some example data (data sources).