By default, capacity instances do not support reserved read and write throughput. You are charged for metered read and write throughput when you read data from or write data to tables in capacity instances. If you are charged for reserved read throughput when you use capacity instances, check whether you use the search index feature.
When you use the search index feature, Tablestore automatically specifies reserved read throughput based on the volume of index data. Therefore, if a search index is created for a table in a capacity instance, you are charged for reserved read throughput. For more information, see Billable items of search indexes.
The price of each billable item of search indexes is the same as the price of each billable item in high-performance instances.