Your team is working on an application that is going to work with a DynamoDB table. At the design stage, you are trying to find out the optimum way to define partition keys and secondary indexes. Which of the following are recommendations for defining secondary indexes? Choose 2 answers from the options given below.

Answer options:

A.Keep the number of indexes to a minimum.
B.Define as many indexes as possible to maximize performance.
C.Avoid indexing tables that experience heavy write activity.
D.Add indexes to tables that experience heavy write activity.

Answer – A and C
The AWS Documentation mentions the following.
Keep the number of indexes to a minimum. Don`t create secondary indexes on attributes that you don`t query often. Indexes that are seldom used contribute to increased storage and I/O costs without improving application performance.
Avoid indexing tables that experience heavy write activity. For example, in a data capture application, the cost of I/O operations required to maintain an index on a table with a very high write load can be significant. If you need to index data in such a table, it may be more effective to copy the data to another table with the necessary indexes and queries there.
Since the documentation mentions this clearly, all other options are invalid.
For more information on working with indexes, please refer to the below URL-
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-indexes-general.html