MYSQL INTERVIEW QUESTION & ANSWERS
11. |
What are the alias available for START TRANSACTION? |
|
BEGIN and BEGIN WORK are aliases of the START TRANSACTION command. |
12. |
Explain COMMIT and ROLLBACK. |
|
COMMIT : The COMMIT statement is used to signify the end of a transaction. At this point all changes to the tables are considered to be durable and will survive server failure.
ROLLBACK : ROLLBACK is used to roll back a transaction to either the state it was in before execution of the transaction or to a certain point prior to where execution is currently occurring. This point is called the SAVEPOINT. |
13. |
Is ROLLBACK transaction supports for DDL statement? |
|
We cannot roll back the transaction by issuing the ROLLBACK statement for DDL statements. |
14. |
Explain SAVEPOINT. |
|
A savepoint is a defined point in a transaction. The SAVEPOINT statement is used to set a savepoint with a name. The ROLLBACK TO SAVEPOINT statement is used to roll back the transaction to the named savepoint specified. Instead of rolling back all the changes in the transaction, ROLLBACK TO SAVEPOINT savepointname rolls back modifications to rows made in the current transaction after the savepoint at savepointname. The data is in the same state it was in at the time the savepoint was reached by the transaction. |
15. |
What statement do you use to delete SAVEPOINT? |
|
To remove the named savepoint from the set of defined savepoints in the current transaction, we can use the RELEASE SAVEPOINT command. |