Data Engineering on Microsoft Azure: IsolationLevel Values for Copy Activity Source | Exam DP-203

IsolationLevel Values for Copy Activity Source

Question

The isolationLevel property in the Copy activity source section describes the transaction locking behavior for the SQL source.

Which of the following are possible values for isolationLevel? (Select all that are applicable)

Answers

Explanations

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A. B. C. D. E. F. G.

Correct Answers: A, B, C and D

isolationLevel describes the transaction locking behavior for the SQL source.

The allowedvalues for this property are: ReadUncommitted, ReadCommitted, , RepeatableRead,Snapshot and Serializable.

If not mentioned, thedefault isolation level of the database is used.

Option A is correct.

Read committed is one of the allowed values for isolationLevel.

Option B is correct.

Read uncommitted is one of the allowed values for isolationLevel.

Option C is correct.

Repeatable Read is one of the allowed values for isolationLevel.

Option D is correct.

Serializable is one of the allowed values for isolationLevel.

Option E is incorrect.

Repeatable Write is not the allowed value for isolationLevel.

Option F is incorrect.

Non-Serializable is not the allowed value for isolationLevel.

Option G is incorrect.

Write Committed is not the allowed value for isolationLevel.

Option H is incorrect.

Write uncommitted is not the allowed value for isolationLevel.

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The isolationLevel property in the Copy activity source section is used to specify the transaction locking behavior for the SQL source. The isolation level determines the degree to which one transaction must be isolated from other concurrent transactions in order to ensure data consistency and prevent concurrency-related issues such as dirty reads, non-repeatable reads, and phantom reads.

The possible values for isolationLevel are as follows:

A. ReadCommitted: This isolation level ensures that a transaction reads only committed data, and therefore, prevents dirty reads. However, it allows non-repeatable reads and phantom reads.

B. ReadUncommitted: This isolation level allows a transaction to read uncommitted data, which can lead to dirty reads. It offers the lowest level of protection against concurrency issues.

C. RepeatableRead: This isolation level ensures that a transaction can read the same data repeatedly, and thus, prevents non-repeatable reads. However, it allows phantom reads.

D. Serializable: This isolation level provides the highest level of protection against concurrency issues by preventing dirty reads, non-repeatable reads, and phantom reads. However, it can also lead to transaction serialization, which can reduce concurrency.

E. Repeatable Write: This is not a valid isolation level.

F. Non-Serializable: This is not a valid isolation level.

G. Write committed: This is not a valid isolation level.

H. Write uncommitted: This is not a valid isolation level.

In summary, the valid isolation levels for the isolationLevel property in the Copy activity source section are ReadCommitted, ReadUncommitted, RepeatableRead, and Serializable.