How to Rollback an Oracle Transaction?

To rollback an Oracle transaction, you can use the ROLLBACK statement. This statement will undo all changes made in the current transaction and restore the data to its state before the transaction began.

You can issue the ROLLBACK statement in SQL*Plus or any other Oracle SQL tool. Make sure you are connected to the appropriate database and have the necessary permissions to rollback the transaction.

Simply type "ROLLBACK;" and execute the statement to rollback the transaction. This will undo any changes made since the transaction was started and revert the data to its original state.

It's important to note that once a transaction has been committed, it cannot be rolled back. In that case, you would need to use a combination of rollback and point-in-time recovery techniques to restore the data to a previous state.

What is the impact of rolling back a transaction in Oracle Database?

Rolling back a transaction in Oracle Database has the following impacts:

1. Data changes made within the transaction are undone: Any changes that were made to the data within the transaction are rolled back, restoring the data to its original state before the transaction was started.
2. Locks on data are released: Any data locks that were acquired by the transaction are released, allowing other transactions to access and modify the data.
3. Uncommitted changes are discarded: Any changes that were made as part of the transaction but not yet committed are discarded, ensuring data consistency and integrity.
4. Transaction is aborted: The transaction is marked as failed and aborted, and any subsequent operations within the transaction are not executed.
5. No impact on other transactions: Rolling back a transaction only affects the specific transaction being rolled back and does not impact other transactions that may be concurrently running.

Overall, rolling back a transaction in Oracle Database ensures that any unintended or erroneous changes made during the transaction are reversed and the database is returned to a consistent state.

How to cancel changes made by a transaction in Oracle?

To cancel changes made by a transaction in Oracle, you can perform a rollback operation. This will undo all the changes made by the transaction and revert the database to its state before the transaction was initiated.

You can rollback a transaction in Oracle using the following steps:

1. Connect to the Oracle database using a tool or command line interface.
2. Identify the transaction that you want to cancel by checking the session ID or transaction ID associated with it.
3. Use the ROLLBACK statement to undo the changes made by the transaction. You can do this by running the following SQL command:

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ROLLBACK;

1. Once the ROLLBACK statement is executed, all changes made by the transaction will be undone, and the database will be reverted to its previous state.

It is important to note that the ROLLBACK operation should be done carefully, as it will permanently undo the changes made by the transaction and cannot be reversed.

How to undo changes made by a transaction in Oracle?

To undo changes made by a transaction in Oracle, you can use the ROLLBACK statement. The ROLLBACK statement is used to undo changes made by a transaction that has not yet been committed.

Here's how you can undo changes made by a transaction in Oracle using the ROLLBACK statement:

1. Start a transaction by using the BEGIN TRANSACTION statement.
2. Make changes to the database within the transaction.
3. If you want to undo the changes made by the transaction, use the ROLLBACK statement. This will rollback all the changes made by the transaction.

Example:

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BEGIN TRANSACTION;

UPDATE employees
SET salary = salary * 1.1
WHERE department_id = 10;

-- If you want to undo the changes made by the transaction
ROLLBACK;

By using the ROLLBACK statement, you can effectively undo changes made by a transaction in Oracle.