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BernsteinConcurrencyControl

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Saved by PBworks
on April 15, 2007 at 6:51:09 pm

Lecture

3 techniques for CC
- locking, 2PL
- timestamp ordering
- optimistic control
Why hard?
- lack of global info
- replication of data: need to update both
  - you want stored items to emulate logical items
model paper uses: TMs with private workspace, DM which handles stored items
dm-read(x): read from DM, dm-prewrite(x): "private writes", dm-write(x): pubic writes
distributed locking
- replication handling
  - primary site/DM
  - primary copy: similar, but partitioned (still need read lock)
  - decentralized: ready any copy, write locks on all copies (mostly used in industry)