Eliminate lost updates and concurrency collisions in SAP Fiori apps. Architect lock master/dependent hierarchies, Total ETag annotations, and optimistic concurrency controls.
// Generating Root Entity BDEF Concurrency...// Generating Item Entity BDEF Concurrency...// Generating CDS ETag Annotations...
etag master protects single-row optimistic locks during active draft editing. total etag evaluates overall BO validity during draft activation to prevent overriding external changes.
Child items must always specify lock dependent by _Parent. Independent locks on child entities create deadlocks in high-concurrency environments.
RAP drafts use SAP Lock Server enqueue locks with 15-minute expirations. The physical database is never held locked while a user has a draft tab open in the browser.