A company is planning on hosting their data warehousing solution in Redshift.
They are trying to decide on the distribution style for their underlying tables.
Which of the following reasons would warrant the use of EVEN distribution style for the underlying tables in Redshift.
Choose 2 answers from the options given below.
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - A and C.
The AWS Documentation mentions the following.
#######
Distribution Styles.
When you create a table, you can designate one of three distribution styles; EVEN, KEY, or ALL.
Even distribution.
The leader node distributes the rows across the slices in a round-robin fashion, regardless of the values in any particular column.
EVEN distribution is appropriate when a table does not participate in joins or when there is not a clear choice between KEY distribution and ALL distribution.
#######
Since this is clearly mentioned in the documentation, the other options are invalid.
For more information on choosing the right distribution style , please refer to the below URL.
https://docs.aws.amazon.com/redshift/latest/dg/c_choosing_dist_sort.htmlRedshift is a columnar database service provided by Amazon Web Services (AWS). It is an efficient data warehousing solution that can store petabytes of structured data and is optimized for querying large datasets. Redshift achieves this efficiency by partitioning data across multiple nodes, which are called slices.
When designing a data warehousing solution in Redshift, choosing the appropriate distribution style for underlying tables is a critical decision. The distribution style determines how data is partitioned across nodes, and it has a significant impact on query performance.
The three distribution styles available in Redshift are EVEN, KEY, and ALL. In this question, we are specifically asked about the EVEN distribution style. The EVEN distribution style evenly distributes data across all nodes in the cluster.
Now, let's discuss the reasons that would warrant the use of the EVEN distribution style:
A. When a table does not participate in joins If a table does not participate in any joins, then the distribution style does not affect query performance. In this case, it may be preferable to use the EVEN distribution style because it provides the most balanced distribution of data across nodes. This can help to ensure that queries run efficiently, and that no single node becomes a bottleneck.
C. When the tables design is new and there is no clear distinction on how the data will be organized When designing a new data warehousing solution, it may be challenging to predict how the data will be organized. In this case, it may be appropriate to start with the EVEN distribution style to provide a balanced distribution of data across nodes. As the data warehousing solution evolves and more is learned about the data, it may be possible to switch to a different distribution style that provides better query performance.
D. When there is a requirement for queries for keys to be co-located. In some cases, queries may require that data be co-located on the same node. For example, if a query joins two tables on a common key, it may be more efficient if the data for those tables is co-located on the same node. However, this requirement may not always be possible or practical, especially if the data is highly skewed. In this case, the EVEN distribution style may be appropriate because it provides a balanced distribution of data across nodes.
B. When the table participates in multiple joins The EVEN distribution style may not be the best option when a table participates in multiple joins. This is because data distribution across nodes in the EVEN distribution style is random and may not be optimized for specific join queries. In this case, it may be more appropriate to use the KEY or ALL distribution style, which can optimize query performance for specific join queries.
In conclusion, the EVEN distribution style is most appropriate when a table does not participate in joins, when the tables design is new and there is no clear distinction on how the data will be organized, and when there is a requirement for queries for keys to be co-located. However, the EVEN distribution style may not be the best option when a table participates in multiple joins.