A company is currently planning on using Redshift to host their data warehouse. Different departments have submitted their files for uploading to various S3 buckets. You need to ensure all the data files are uploaded efficiently to the cluster with the least maintenance overhead. Which of the following method would you incorporate for this scenario?

Answer options:

A.Use a manifest file for the COPY command
B.Ensure all the buckets are made public
C.Copy all the files to a central S3 bucket
D.Ensure versioning is enabled for the bucket

Answer – A
This is given in the AWS Documentation
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Using a Manifest to Specify Data Files
You can use a manifest to ensure that the COPY command loads all of the required files, and only the required files, for a data load. Instead of supplying an object path for the COPY command, you supply the name of a JSON-formatted text file that explicitly lists the files to be loaded. The URL in the manifest must specify the bucket name and full object path for the file, not just a prefix. You can use a manifest to load files from different buckets or files that do not share the same prefix. The following example shows the JSON to load files from different buckets and with file names that begin with date stamps.
{
"entries": [
{"url":"s3://mybucket-alpha/2013-10-04-custdata", "mandatory":true},
{"url":"s3://mybucket-alpha/2013-10-05-custdata", "mandatory":true},
{"url":"s3://mybucket-beta/2013-10-04-custdata", "mandatory":true},
{"url":"s3://mybucket-beta/2013-10-05-custdata", "mandatory":true}
]
}
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Option B is incorrect since this is not a requirement and can also pose to be a security issue
Option C is incorrect since this would be in inefficient process
Option D is incorrect since this is not a requirement for the COPY process
For more information on using manifest files, please refer to the below URL
https://docs.aws.amazon.com/redshift/latest/dg/loading-data-files-using-manifest.html