Concurrency
Within One Client different from Between Clients
Transactions
- Neither Commercial nor Software Engineering Database
Locking
- I don’t want to lose my work: Security, ability to write data to database
- I don’t want to stop work because data isn’t available: Fine granularity
- I want to be able to undo changes: Transaction abort
- I don’t want to waste time working from old data: Distribute updates
- I want to see others’ work: Minimal locking