Concurrency Control

Concurrency Control

1. Two phase locking

   • Plain
     • Growing
     • Shrinking
   • Strict
     • Recoverable
   • Rigorous
     • Cascadeless
   • Practical protocol

2. Operation

   • Unlock
   • Lock
     • Shared
     • Exclusive

3. Deadlock

   • Prevention
     • Wait die
       • Non preemptive
     • Wound wait
       • Preemptive
   • Timeout
   • Detection
     • Wait for graph

4. Degree of isolation

   • Dirty read
   • Phantom read
   • Unrepeated read

5. Timestamp based

   • No locks
   • Restart
   • Write max
   • Read max
   • Thomas write rule

6. Graph based

   • Exclusive lock
   • Partial order
   • Protocol
     • Lock once
     • Lock any
     • Unlock any order
     • Lock if parent