Transcript Cohera

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Dewitt Was Right

By Michael Stonebraker

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DWR

Grids (cells, blades)

Cheapest computing on the planet (coming)

Shared nothing

How does this relate to data bases?

Go read about Gamma (circa 1985) M.I.T.

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But…….

Buy the dreaded 2 phase commit

Bad sandbox to play in M.I.T.

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Suppose

Insist on replication of every table

Done by SLAC, Walmart and most warehouses

Disk space is cheap

Replicas need not be organized the same way

Process every update twice (independently)

In general provide K-safety M.I.T.

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Crash Recovery

Rebuild damaged object from a replica, not from a redo log

Get rid of

Redo (but not undo)

Truncate undo log at EOT

2 phase commit (prepare message) M.I.T.

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Net Result - No Mohan

New sandbox:

How to efficiently rebuild objects (especially partially damaged ones) from replicas M.I.T.