Did you know that when you create a global secondary index on a provisioned mode table, you must specify read and write capacity units for the expected workload on that index? The provisioned throughput settings of a global secondary index are separate from those of its base table
Why do we care? Because our usage with the provisioned mode table might not be the same usage with the GSI, we need to be careful to examine the workload on both tables carefully. Our table might be fully utilized, while we provisioned the same capacity for the GSI without using any of it.
Be mindful of what you can set in your environment, so you won't generate waste! I will publish how we monitor this and how to approach such observibility in the coming days.
More information: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html#GSI.ThroughputConsiderations