Allianz Financial Services (AFS) is a banking group offering end-to-end banking and financial solutions in South East Asia through its consumer banking, business banking, Islamic banking, investment finance and stock broking businesses as well as unit trust and asset administration, having served the financial community over the past five decades. AFS uses Redshift on AWS to fulfill the data warehousing needs and uses S3 as the staging area to host files.
AFS uses other services like DynamoDB, Aurora, and Amazon RDS on remote hosts to fulfill other needs.
The team uses load the data from different data sources using COPY command.
What are the best practices to load using COPY command to copy the data from S3? select 3 options.
Click on the arrows to vote for the correct answer
A. B. C. D.Answer : A,B,D.
Option A is correct -The COPY command leverages the Amazon Redshift massively parallel processing (MPP) architecture to read and load data in parallel from files in an Amazon S3 bucket.
You can take maximum advantage of parallel processing by splitting your data into multiple files and by setting distribution keys on your tables
https://docs.aws.amazon.com/redshift/latest/dg/t_Loading-data-from-S3.htmlOption B is correct -Amazon Redshift automatically loads in parallel from multiple data files.
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
https://docs.aws.amazon.com/redshift/latest/dg/c_best-practices-single-copy-command.htmlOption C is incorrect -Amazon Redshift automatically loads in parallel from multiple data files.
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
https://docs.aws.amazon.com/redshift/latest/dg/c_best-practices-single-copy-command.htmlOption D is correct -Amazon Redshift automatically loads in parallel from multiple data files.
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
https://docs.aws.amazon.com/redshift/latest/dg/c_best-practices-single-copy-command.htmlThe COPY command is an efficient and easy way to load data into Amazon Redshift from various data sources, including S3. Here are the best practices to load data using COPY command:
Split your data into multiple files and upload to S3: This is important because Redshift works better with smaller files than larger files. It's recommended to split large files into smaller ones and upload them to S3. This also enables Redshift to utilize parallelism while loading data from S3.
Use multiple concurrent COPY commands to load one table from multiple files resulting in parallel load: When loading data from multiple files, it's best to use multiple concurrent COPY commands to load data in parallel. This reduces the overall time taken to load data and ensures better performance.
Use a manifest file: When loading data from S3, it's recommended to use a manifest file that lists all the files to be loaded. This ensures that all the files are loaded and none are missed. The manifest file can also be used to specify various options like file compression, encryption, and data format.
Use the correct data format: The COPY command supports various data formats like CSV, JSON, AVRO, and more. It's recommended to use a data format that is optimized for Redshift. For example, CSV is a popular format that is supported by most tools and can be easily loaded into Redshift.
Run a single COPY command to load the table: While it's recommended to use multiple concurrent COPY commands to load data in parallel, it's important to ensure that each table is loaded using a single COPY command. This ensures that the data is loaded correctly and avoids any issues with data consistency.
Use VACUUM process at the end of the load, if the table has a sort column defined: If the table has a sort key defined, it's recommended to run the VACUUM process at the end of the load. This ensures that the data is sorted correctly and avoids any issues with data consistency.
In summary, to load data from S3 using the COPY command in Redshift, it's recommended to split large files, use multiple concurrent COPY commands, use a manifest file, use the correct data format, run a single COPY command per table, and use the VACUUM process if the table has a sort key defined.