AWS Certs - DBS所有题目

【所有题目】1. A data engineer is about to perform a major upgrade to the DDL contained within an Amazon Redshift cluster to support a new data warehouse application. The upgrade scripts will include user permission updates, view and table structure changes as well as additional loading and data manipulation tasks. The data engineer must be able to restore the database to its existing state in the event of issues. Which action should be taken prior to performing this upgrade task?

A. Run an UNLOAD command for all data in the warehouse and save it to S3.

B. Create a manual snapshot of the Amazon Redshift cluster.

C. Make a copy of the automated snapshot on the Amazon Redshift cluster.

D. Call the waitForSnapshotAvailable command from either the AWS CLI or an AWS SDK.

正确答案: B

Correct answer is B as a manual snapshot needs to be taken to be able to restore Redshift to the point before upgrade.,Refer AWS documentation - Redshift Snapshots,Snapshots are point-in-time backups of a cluster. There are two types of snapshots: automated and manual. Amazon Redshift stores these snapshots internally in Amazon S3 by using an encrypted Secure Sockets Layer (SSL) connection.,Amazon Redshift automatically takes incremental snapshots that track changes to the cluster since the previous automated snapshot. Automated snapshots retain all of the data required to restore a cluster from a snapshot. You can create a snapshot schedule to control when automated snapshots are taken, or you can take a manual snapshot any time.,When you restore from a snapshot, Amazon Redshift creates a new cluster and makes the new cluster available before all of the data is loaded, so you can begin querying the new cluster immediately. The cluster streams data on demand from the snapshot in response to active queries, then loads the remaining data in the background.,When you launch a cluster, you can set the retention period for automated and manual snapshots. You can change the retention period for automated and manual snapshots by modifying the cluster. You can change the retention period for a manual snapshot when you create the snapshot or by modifying the snapshot.,You can take a manual snapshot any time. By default, manual snapshots are retained indefinitely, even after you delete your cluster. You can specify the retention period when you create a manual snapshot, or you can change the retention period by modifying the snapshot. If you create a snapshot using the Amazon Redshift console, it defaults the snapshot retention period to 365 days.,If a snapshot is deleted, you can't start any new operations that reference that snapshot. However, if a restore operation is in progress, that restore operation will run to completion.,Option A is wrong as it would only copy the data.,Option C is wrong as you cannot copy the automated snapshot. Also, automated snapshot are controlled by time and size and would not represent the data before upgrade.,Option D is wrong as waitForSnapshotAvailable needs to be called after triggering the manual snapshot creation and it can be verified from console as well.