Best Approach for Storing Data in DynamoDB for Date Range Queries

Answer: B.

Option A is incorrect because DynamoDB does not have a Date data type.

Option B is CORRECT because AWS SDK for Java provides direct data type mapping from Date Java data type to DynamoDB String type with date values stored in ISO 8601 format.

Options C and D are incorrect because AWS SDK for Java provides direct data type mapping from Date Java data type to DynamoDB String type with date values stored in ISO 8601 format.

Additionally, ISO 8601 date format allows for simpler and more efficient date querying than dates stored in epoch format as no conversion is required.

Reference:

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBMapper.DataTypes.html https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html#HowItWorks.DataTypes

The recommended approach to store date range data in a DynamoDB table for a Java application is to use the String data type and ISO 8601 format.

Here's why:

1. Using the Date data type: DynamoDB does not have a native Date data type. However, if you use a programming language such as Java, you can represent dates as objects of the java.util.Date class. However, the Date object cannot be directly stored in DynamoDB. You will need to convert the Date object to a string or number before storing it in DynamoDB. Additionally, querying by date range is not possible with the Date data type.

2. Using the String data type and Epoch format: Epoch time is the number of seconds that have elapsed since January 1, 1970, UTC. Storing dates as Epoch time in DynamoDB is an option, but querying by date range becomes difficult since DynamoDB does not support range queries on non-String data types. Querying by range on Epoch time will also require manual conversion to human-readable date format which can be challenging and error-prone.

3. Using the Number data type and Epoch format: Similar to option 2, using the Number data type to store Epoch time has the same disadvantages. Querying by range on Number data types is not supported in DynamoDB.

4. Using the String data type and ISO 8601 format: ISO 8601 is a standard format for representing dates and times in a machine-readable format. It provides a human-readable format and sorts lexicographically. This makes it easy to query for date ranges. DynamoDB supports range queries on String data types. Additionally, using a standard format like ISO 8601 ensures consistency across your application and avoids potential issues with date formatting and parsing.

In summary, using the String data type and ISO 8601 format is the recommended approach for storing date range data in a DynamoDB table for a Java application.