To answer this question, you need to understand the differences between the commands DROP, DELETE, CASCADE, and TRUNCATE in the context of deleting data from a table.
Let's go through each option to understand why it is correct or incorrect:
Option A) DROP - The DROP command is used to delete an entire table from the database. It not only deletes the data but also removes the table structure and all associated objects. However, it is not the correct command for deleting data from a table without writing to the rollback segment.
Option B) DELETE - The DELETE command is used to delete specific rows from a table based on a given condition. It is commonly used to selectively remove data from a table. However, when using the DELETE command, the deleted data is written to the rollback segment for potential rollback operations.
Option C) CASCADE - The CASCADE keyword is used in conjunction with other commands, such as DROP or ALTER, to specify that the action should be cascaded to dependent objects. It is not a command for deleting data from a table without writing to the rollback segment.
Option D) TRUNCATE - The TRUNCATE command is used to remove all data from a table. It is a fast and efficient way to delete data because it does not generate any rollback information and does not write to the rollback segment. TRUNCATE is the correct command for deleting all data from a table without writing to the rollback segment.
Therefore, the correct answer is D) TRUNCATE. This option is correct because the TRUNCATE command will delete all data from a table without writing to the rollback segment.