Understanding Transaction Terminologies: Question and Answer

Q.1. What is The Meaning of Beginning a Transaction?

Ans: Beginning a transaction involves specifying that all subsequent operations occurring after the start of the transaction are assumed to be within the transaction.

Q.2. What is The Definition of Rolling Back a Transaction?

Ans: Rolling back a transaction refers to undoing operations performed since the start of the transaction, thus restoring the affected data to its original state. This action is taken in the event of a failure.

Q.3. What Does Committing a Transaction Mean?

Ans: Committing a transaction means making all operations that have occurred since the beginning of the transaction permanent. This action is performed in the event of a successful transaction.

Q.4. What is The concept of Dirty Read?

Ans: A Dirty Read occurs when data that has not yet been committed is read. For instance, when transaction B is blocked by transaction A, and dirty reads are allowed, transaction B may end up reading transaction A's changes even though they have not yet been committed.

Q.5. What Does Nonrepeatable Read Mean?

Ans: Nonrepeatable Read refers to a situation in which transaction B modifies the data that transaction A was working with during transaction A's lifetime. Consequently, transaction A reads modified data, and the original read is no longer possible.

Q.6. What is Meant by Phantom Read?

Ans: Phantom Read describes a scenario in which the number of rows changes between two reads within the same transaction, similar to a non-repeatable read. Phantom rows are those rows that differ between the two reads.

Conclusion

we have explored the meaning of various transaction terminologies. If you still find it challenging to understand the concept of a phantom read problem, including when it occurs in SQL Server and how to address it, consider exploring online SQL certifications available in the market. These certifications can provide valuable insights into handling transaction isolation level concurrency events, such as the phantom read phenomenon, through SQL Server online training.