DBeaver claims to be the best database editor. Thanks to some bad UI, something as simple as switching the database schema in the SQL editor is impossible. This is one of the most common activities for anyone using a database manager and SQL editor. You want to run your saved SQL script against a different database or schema. In SQL Developer, this is as simple as can be. Just select the different schema from the dropdown. In DBeaver, you can't. Select the database displayed at the top of the editor by double-clicking or pressing Ctrl+0. It displays a popup that maddeningly shows all the other schemas but you can't actually select them. I'm not sure why there is a popup showing the other schemas in DBeaver. You can see them all in the database navigator in the sidebar. It seems the popup was designed to allow selecting a different schema but there are no buttons, no instructions explaining how to select a different schema, and apparently no functionality in this popup other than to see the databases that you can't select. They sit there and taunt you. It should be as simple as clicking on one and selecting a button like "Select" or even double-clicking on one to select it, but no buttons appear and you can click until your fingers are sore and nothing happens. For the complete failure to implement the most basic and common functionality, DBeaver earns a massive fail.
Update: it turns out that you can select a different database schema in the "Choose catalog/schema" dialog that pops up when you select it at the top of the editor window or press Ctrl+0. Click on the database in the left pane then double-click on the schema in the right pane, which closes the dialog and selects the other database.
This is about as bad as UI gets. No buttons, no titles at the top of the panes describing what they are, no hints as to what this page does or how to select a different database and schema. Clearly designed by a software engineer with a penchant for using Easter Eggs instead of useful UI. Obviously not designed by a UX person. Still a massive fail for DBeaver, even though the ability to switch databases is technically there. It just requires trying everything under the sun to discover the Easter Egg embedded in this page. Utterly awful.