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2 Basic techniques for mapping virtual processor partitions to actual processor
partitions are as follows.
- Round Robin - Map Virtual Processor i to Real Processor i mod n.
- Processor scheduling -
- 1.
- Estimate cost Ci of joining the tuples of Ri and Si such
that
Ciest = Riest + Siest + Ri Join Siest
where
Riest is the number of R tuples mapped to partition i
Siest is the number of S tuples mapped to partition i
and
Ri Join Si
est is an estimate of the number of tuples in Ri Join Si .
- 2.
- Sort in decreasing order of estimated cost.
- 3.
- Using the LPT (Lowest Processor Time) Heuristic schedule (map) the virtual
processors to the least loaded processor.
DBMS
1999-03-11