Give an example of a schedule of two transactions that preserves database consistency (the database satisfies its integrity constraints), but nevertheless yields a final database that does not reflect the effect of both transactions.

What will be an ideal response?


Two interleaved deposit transactions of |S10:
r1(bal) r2(bal) w1(bal = bal + |S10) w2(bal = bal + |S10)
The integrity constraint is bal ? 0, and the update made by transaction T1 is lost.

Computer Science & Information Technology

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