And Kexi's well worth it, especially if you need to emphasize visuals in a database. Within minutes, literally, you can create a relational data base with all the flexibility and versatility of Access but with greater ease. As with Access, the database structure is created in a series of tables, but without the fussiness Access imposes on defining far more things than you want to define. My favorite feature is that everything from tables to queries, to forms, are stored in the database, letting you move or share data and design by moving a single file.
You can use Kexi as a stand-along or connected to relational SQL database servers. You'll finally bump into limits, even with the full versions, if you keep pushing the complexity of your design, but Kexi is still a database that fills a deep hole.