[prev] 23 [next]

Deadlock (cont)

Properties of deadlock handling methods:
  • both wait-die and wound-wait are fair
  • wait-die tends to
    • roll back tx's that have done little work
    • but rolls back tx's more often
  • wound-wait tends to
    • roll back tx's that may have done significant work
    • but rolls back tx's less often
  • timestamps easier to implement than waits-for graph
  • waits-for minimises roll backs because of deadlock