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Say n transactions follow a strict serializable schedule i.e. serialize themselves using strict2PL or the like. Now say a (n+1)th transaction comes in to run concurrently with the others and does not follow strict2PL. Can we still safely say that it will read data only commited data from others.

Thanks

Lipika Deka
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2 Answers2

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A schedule in which a transaction can neither read or write an item X until the last transaction that wrote X has committed.

Ishara Samintha
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Here strictness means that if you have two transactions Trans1 and Trans2, if a write operation of Trans1 comes before a conflicting operation of Trans2(read or write), then the commit event of Trans1 will also come before that conflicting operation of Trans2. Strictness is just to allow efficient recover of databases from failure.

for more see this page- http://en.wikipedia.org/wiki/Two-phase_locking

Caffeinated
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