CRIUS: User-Friendly Database Design

Non-technical users are increasingly adding structures to their data.This gives rise to the need for database design. However, traditionaldatabase design is deliberate and heavy-weight, requiring techni-cal expertise that everyday users may not possess. For this reason,we propose that users of personal data management applicationsshould be able to create and refine data structures in an ad-hoc wayover time, thereby “organically” growing their schemas. For thispurpose, we develop a spreadsheet-like direct manipulation inter-face. We show how integrity constraints can still provide value,even in this scenario of frequent schema and data modifications.We also develop a back-end database implementation to supportthis interface, with a design that permits schema changes at a lowcost.We have folded these ideas into a system, called CRIUS, whichsupports a nested data model and a graphical user interface. Fromthe user’s perspective, the chief advantages of CRIUS are its sup-port for simple schema definition and modification through an in-tuitive drag-and-drop interface, as well as its guidance towards userdata entry based on incrementally updated data integrity. We haveevaluated CRIUS by means of user studies and performance stud-ies. The user studies indicate that 1) CRIUS makes it much eas-ier for users to design a database, as compared to state-of-the-artGUI database design tools, and 2) CRIUS makes user data entrymore efficient and less error-prone. The performance experimentsshow that 1) the incremental integrity update in CRIUS is very ef-ficient, making the data entry guidance applicable and 2) the back-end database implementation in CRIUS significantly improves theperformance of schema update tasks, without a significant impacton other operations.