Exam AWS Certified Data Analytics - Specialty topic 1 question 35 discussion

D? https://docs.aws.amazon.com/redshift/latest/dg/loading-data-files-using-manifest.html

Correct answer is D as a manifest file can be used to load the data. Also, its recommended to have a single COPY command instead of multiple concurrent COPY commands for performance. Use the COPY command to load a table in parallel from data files on Amazon S3. You can specify the files to be loaded by using an Amazon S3 object prefix or by using a manifest file. Amazon Redshift can automatically load in parallel from multiple compressed data files. However, if you use multiple concurrent COPY commands to load one table from multiple files, Amazon Redshift is forced to perform a serialized load. This type of load is much slower and requires a VACUUM process at the end if the table has a sort column defined. Options A, B & C are wrong as they add unnecessary work and cost.

Ans D, single COPY command for performance and manifest file for loading data

datalake s3 -> dw redshift problems copying files using copy-by-prefix need a solution without increasing costs A) emr is expansive b) aurora needs effort configuration and glue needs development effort c) glue job needs a development effort and copying all files to the same prefix will create a problem... which file goes to which table? d) manifest file is the best option because you can specify exactly the prefix/key to your copy command

D: manifest file is valid option

D: I passed the test

You can use a single copy command with manifest file, containing different S3 locations. This will speed up the COPY process.

Selected Answer: D

My Answer is D

D is correct

Ans D A = wrong, no segregation, increased cost. B = wrong, no segregation, unnecessary work, increased cost. C = wrong, no segregation, increased cost. This is a question on how COPY command work. In general you should use only one COPY command because Redshift will load data in parallel, if you use many COPYs Redshift will have to load data in sequential manner. https://docs.aws.amazon.com/redshift/latest/dg/c_best-practices-single-copy-command.html https://docs.aws.amazon.com/redshift/latest/dg/r_COPY_command_examples.html#copy-command-examples-manifest

D is the right answer

My answer is D

D is right answer.

From the link:https://docs.aws.amazon.com/redshift/latest/dg/loading-data-files-using-manifest.html "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" So answer is D

Using manifest file is the right choice. So option D.

Yes D is the right answer