
Concept explainers
Explanation of Solution
Concurrency control:
The purpose of concurrency control is to ensure the serializability of transaction in a multiuser
Common problems with concurrent transaction execution:
Concurrency transaction is one or more transactions are processed on same time. During the concurrency transaction execution the following problems can occur in the transaction. They are:
- Lost updates
- Uncommitted data
- Inconsistent retrievals
Lost updates:
A data can be lost when the two different transactions want to update same field or row within the database at the same time.
- For example: if the transactions “T1” and “T2” want to update the same element and one of the updates is lost or overwritten by other transactions.
Uncommitted data:
The data of the transactions are not committed when the transactions are executed concurrently...

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Chapter 10 Solutions
Database Systems: Design Implementation & Management
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