Questions

1. Define the term transaction. What is the meaning of implicit transaction?
2. What are the functions of the following SQL commands: BEGIN, END, COMMIT, ROLLBACK, and SAVEPOINT?
3. Assuming you are working with an environment that does not support transactions, give a solution to mitigate the following scenario: A developer performed a bulk upload on a non-empty table, and during the upload, the power shut down. The developer would like to restore the initial state.
4. What is the difference between concurrency and parallelism? Does PostgreSQL support both?
5. What is MVCC? What negative impact does it have on the database design? How does PostgreSQL mitigate this impact?
6. List the transaction isolation levels. What is the default transaction isolation level in PostgreSQL?
7. List the side effects of each transaction isolation level and explain them briefly.
8. What are the levels of...