Strict Two-Phase Locking
Lock compatibility
|
shared
| exclusive
|
shared |
|
X |
exclusive |
X |
X |
- X: Locks are incompatible.
- Read an item after obtaining a shared lock on it.
- Write an item after obtaining an exclusive lock on it.
- Any number of transactions can read an item at the same time.
- At most one transaction can write an item at any time.
|