PolarDB offers three billing methods for storage space, each with a different pricing plan: pay-as-you-go with a storage plan (recommended), pay-as-you-go, and subscription.
Introduction and comparison
The PolarDB storage classes PSL4 and PSL5 are billed based on storage capacity. The following table compares the three billing methods.
Billing method | Storage cost calculation | Benefits | Scenarios |
Pay-as-you-go by capacity + Storage plan | Storage costs are first deducted from your purchased storage plan. If your data volume exceeds the plan's capacity, the excess is billed as pay-as-you-go by capacity. | Flexible and cost-effective |
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Pay-as-you-go by capacity | Charged based on the actual storage space your data uses. Fees are deducted from your account hourly. | Flexible | Small total storage usage for all clusters in a region under your Alibaba Cloud account, with frequent fluctuations in business volume. |
Subscription by space | Pay for the cluster's storage space in advance when you create it. | Cost-effective | Total storage usage for all clusters in a region under your Alibaba Cloud account is less than 10 TB, and business volume does not fluctuate frequently. |
Scenarios
Scenario 1: High total storage usage across all clusters in a region
Assume that an Alibaba Cloud account has multiple clusters of the PSL5 storage type in a region within the Chinese mainland, and the total storage usage of all clusters is constant at 10 TB or 50 TB. The following table compares the storage fees for different billing methods.
Total storage usage of all clusters
Billing method
Total storage fee
10 TB
Pay-as-you-go + storage plans
CNY 21,000/month
Pay-as-you-go
CNY 35,000/month
Subscription
CNY 22,700/month
50 TB
Pay-as-you-go + storage plans
CNY 96,000/month
Pay-as-you-go
CNY 175,000/month
Subscription
CNY 113,500/month
Scenario 2: Small total storage usage across all clusters in a region, but frequent business fluctuations
Assume that an Alibaba Cloud account has multiple clusters of the PSL5 storage type in a region within the Chinese mainland, and the storage usage of each cluster fluctuates significantly. The total storage usage of all clusters ranges from 1,000 GB to 4,000 GB. In a given month, the total storage usage stays below 3,000 GB for three weeks and exceeds 3,000 GB for one week.
If you use Subscription, there is a risk of service interruption caused by disk space exhaustion when the purchased storage is fully consumed. Therefore, you need to purchase 4,000 GB of storage capacity based on the estimated peak storage usage.
If you use Pay-as-you-go + storage plans, there is no risk of service interruption. Therefore, you can purchase storage plans based on 3/4 of the estimated peak storage usage (in this example, a 3,000 GB storage plan is purchased to offset the total storage usage of all clusters), and pay for the excess usage on a pay-as-you-go basis.
Billing method
Total storage fee
Calculation process
Pay-as-you-go + storage plans
CNY 8,616.48/month
In this billing method, storage plans are purchased based on 3/4 of the estimated peak storage usage. In this example, a 3,000 GB storage plan is purchased to offset the total storage usage of all clusters. Based on the scenario, the total storage usage exceeds 3,000 GB but remains below 4,000 GB for one week. Charges are calculated based on the peak storage usage of 4,000 GB. The total fee is calculated as follows:
CNY 7,800/month (3,000 GB storage plan fee) + 1,000 GB × CNY 0.00486/GB/hour × 24 hours × 7 days = CNY 8,616.48/month
Subscription
CNY 9,080/month
In this billing method, there is a risk of service interruption caused by disk space exhaustion when the purchased storage is fully consumed. Therefore, you need to purchase 4,000 GB of storage capacity based on the estimated peak storage usage. The total fee is calculated as follows:
CNY 2.27/GB/month × 4,000 GB = CNY 9,080/month
Scenario 3: Small total storage usage across all clusters in a region, and infrequent business fluctuations
Assume that an Alibaba Cloud account has multiple clusters of the PSL5 storage type in a region within the Chinese mainland, and the total storage usage of the clusters is constant at 500 GB and 800 GB respectively. The following table compares the storage fees for different billing methods:
Total storage usage of all clusters
Billing method
Total storage fee
500 GB
Pay-as-you-go + storage plans
CNY 1,750/month
Pay-as-you-go
CNY 1,750/month
Subscription
CNY 1,135/month
800 GB
Pay-as-you-go + storage plans
CNY 2,800/month
Pay-as-you-go
CNY 2,800/month
Subscription
CNY 1,816/month
For the prices mentioned in the preceding examples, see Pay-as-you-go + storage plans billing rules, Pay-as-you-go billing rules, and Subscription billing rules.
Price estimation
PolarDB provides the price calculator and resource plan calculator. You can use the calculators to obtain information about the product pricing, estimate costs, and select a product type that meets your business requirements.
Price calculator: allows you to estimate the overall cost based on the details and storage capacity of the cluster that you select.
Resource plan calculator: allows you to estimate required compute capacity and storage capacity based on your business requirements and usage duration. The calculator can also provide recommendations on the specifications of storage plans and compute plans for clusters with defined specifications.