concurrency control

concurrency control

1. Degree of isollation

   • dirty read
   • phantom read
   • unrepeated read

2. timestamp based

   • no locks
   • restart
   • write max
   • read max
   • Thomas write rule

3. Deadcklock

   • detection
     • wait for graph
   • prevention
     • wound wait
       • preemtive
     • wait die
       • non preemtive
   • timeout

4. Graph based

   • partial order
   • Executive lock
   • Protocol
     • Lock if parent
     • unlock any order
     • lock once
     • lock any

5. Operation

   • Unlock
   • lock
   • Shared
   • Exclusive

6. Two phase locking

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