Search index-based queries require extra space to store indexed data and increase read throughput. This topic describes billable items, billing formulas, and billing examples of search indexes.
Usage notes
Billable items of indexes are independent of data tables.
The price of each billable item of a search index is the same as the price of each billable item in a high-performance instance. For more information about pricing, see Tablestore Pricing.
Billable items
Billable item | Billing method | Description | |
Data size | Pay-as-you-go | Unit: GB. If the data size is not an integer, the data size is rounded up to an integer. Tablestore charges you for the total volume of indexed data on an hourly basis. The utilization of system resources varies based on the field types and index types. You are charged for indexed data based on the volume of data that is compressed after you create indexes. The volume of raw data in a data table does not affect the billing. | |
Read throughput | Reserved read throughput | Pay-as-you-go | Unit: CU. Tablestore automatically specifies a reserved read throughput based on the indexed data size. The fees for reserved read throughput are calculated based on the following operations:
If the read throughput during search index-based queries is smaller than or equal to the reserved read throughput, you are charged based on the unit price of reserved read throughput. For example, the reserved read throughput is 10,000 CUs for an index, each index-based query reads 10 rows, and the size of each row is less than 4 KB. If the number of queries per second (QPS) is less than 1,000, the actual read throughput that is calculated is less than the reserved read throughput and no extra fees are generated. Calculation of reserved read throughput: The reserved read throughput is proportional to the size of the indexed data and the number of rows of the indexed data. For example, 1 GB or 2 million rows of indexed data correspond to a reserved read throughput of 10 CUs. If the reserved read throughput value that corresponds to the data size is different from the reserved read throughput value that corresponds to the number of rows, the system uses the larger value as the reserved read throughput. Important If the data size is less than 200 MB and the number of rows is less than 400,000, the reserved read throughput for Tablestore must be 20 CUs. This value is suitable for tests that are performed on a small volume of data. If the data size is greater than or equal to 200 MB, or the number of rows is greater than or equal to 400,000, the reserved read throughput must be at least 100 CUs. |
Metered read throughput | Pay-as-you-go | You are charged for the portion of the actual read throughput that exceeds the reserved read throughput based on the pay-as-you-go billing method. Unit: CU. | |
Outbound traffic over the Internet | Pay-as-you-go | You are charged for the outbound traffic that is sent over the Internet. Unit: GB. | |
Billing formulas
The following table describes how to calculate the data size and read throughput of a search index.
Billable item | Formula | Description |
Data size |
| The Size variable specifies the size of the compressed indexed data. |
Read throughput | Reserved read CUs per index: Read CUs per query: |
|
Billing examples
The prices in the following table are provided only for reference. For more information, see Tablestore Pricing.
Storage volume | Number of rows | Billing |
8 GB | 9 million |
You are charged for the portion of actual read throughput that exceeds the reserved read throughput based on the pay-as-you-go billing method. The fees for outbound traffic that is sent over the Internet in search indexes are the same as the fees for outbound traffic that is sent over the Internet in data tables. |
100 GB | 300 million |
You are charged for the portion of actual read throughput that exceeds the reserved read throughput based on the pay-as-you-go billing method. The fees for outbound traffic that is sent over the Internet in search indexes are the same as the fees for outbound traffic that is sent over the Internet in data tables. |
FAQ
Why are reserved read CUs generated when I use a search index?
Tablestore automatically specifies a reserved read throughput based on the indexed data size. The fees for reserved read throughput are calculated based on the following operations:
When you create a search index, Tablestore reads data from the data table for which the search index is created. This process increases read throughput.
Tokenization also increases read throughput when you create a search index. Fees that are generated for tokenization are included in the bill that is generated for the reserved read throughput.
To ensure index performance and query performance, some indexed data is loaded to the memory in advance and remains in the memory. This increases read throughput. Fees that are generated based on the read throughput are also included in the bill that is generated for the reserved read throughput.
Can I modify the reserved read CU settings for a search index?
No. You cannot modify the reserved read CU settings for a search index. The number of reserved read CUs is positively related to the data size and the number of rows. Reserved read CUs are used when you create a search index and for memory maintenance. If you want to reduce the number of reserved read CUs, you can reduce the size of the index or the number of rows.
Why am I charged for high-performance storage and high-performance read and write CUs when I use a search index in a capacity instance?
When you use a search index, extra space is required to store indexed data and search index-based queries increase read throughput. The price of each billable item of a search index is the same as the price of each billable item in a high-performance instance. Therefore, when you use a search index in a capacity instance, you are charged for high-performance storage and high-performance read and write CUs.
How do I view metering data of search indexes?
You can view metering data such as the storage volume, reserved read CUs, and number of rows of search indexes in the Tablestore console. For more information, see View the metering data of search indexes.
Can I use reserved CU plans to offset the fees that are generated for reserved read throughput of search indexes?
Yes. You can use reserved CU plans to offset the fees that are generated for reserved read and write CUs, including the reserved read throughput of search indexes.