DATABASE SYSTEM CONCEPTS LCPO
7th Edition
ISBN: 9781265586577
Author: SILBERSCHATZ
Publisher: MCG
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Chapter 25, Problem 2PE
Explanation of Solution
a)
Sequence counter in two phase manner:
- The sequence counter remains locked in two phase in exclusive mode till it acquires the lock from other transaction
- There might be data conflict during the transaction with...
Explanation of Solution
b)
i. Improving the concurrency using counters:
- When the transaction abort it does not create any problems and increment operation can be performed easily on the counter.
- It cannot retain its original position during an abort. But it remains as it stands.
- So, there might be gaps in the sequence number as the counter cannot be restored to its previous value.
- These values are assigned to its aborted transactions.
ii. Gaps in sequence numbers:
- For example assume the counter value which cannot restore to its previous value during transactions...
Expert Solution & Answer
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Chapter 25 Solutions
DATABASE SYSTEM CONCEPTS LCPO
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