If you use the subscription billing method for a cluster, you must pay upfront for the compute nodes when you purchase the cluster. The payment does not include the storage fees. Storage fees are deducted from your account on an hourly basis. Pay-as-you-go bills may still be generated when you use the subscription billing method.
Scenarios
If the workloads are heavy, have small fluctuations, and infrequently change, such as if a scale-out is not required in a year, we recommend that you purchase a subscription cluster. The subscription billing method is more cost-effective for heavy workloads than the pay-as-you-go method.
Combination with storage plans
The storage capacity of a PolarDB cluster is automatically scaled based on the amount of stored data. You do not need to specify the storage capacity. You are charged for the storage capacity that you use. The storage fee for each PolarDB cluster is charged based on the data volume and retention period. If you require a larger storage capacity, such as 1,000 GB or more, we recommend that you purchase storage plans to reduce costs.
A storage plan is a subscription-based resource plan provided by PolarDB. Storage plans can be used to offset multiple types of storage usage in PolarDB, including cluster storage usage, level-1 backup storage usage beyond the free quota, level-2 backup storage usage, log backup storage usage, cold data storage usage, and Serverless storage usage. Storage plans help reduce costs. A storage plan of a larger capacity and a longer duration offers more savings.
For example, a monthly storage plan provides 10% to 45% savings when compared with the price of a comparable pay-as-you-go cluster. The longer the duration of the plan, the more savings you get. If you purchase annual storage plans, you can save an additional 15% off the monthly price.
Storage plans can be applied to all PolarDB clusters in the regions that are specified by the Resource Plan Type parameter. You can select Chinese Mainland or Outside Chinese Mainland for the parameter.
If the capacity of your storage plan is insufficient, you can purchase an additional storage plan or upgrade the storage plan. You cannot downgrade storage plans. For information about how to upgrade a storage plan, see the "Upgrade a storage plan" section of the Renew or upgrade a storage plan topic.
If the amount of the storage that is used exceeds the capacity of your storage plan, you are charged for the additional storage resources based on the pay-as-you-go billing method.
For example, if you create three PolarDB clusters each of which requires 400 GB of storage, you can purchase a storage plan with 1,000 GB of capacity for the clusters. The excess 200 GB of storage usage is billed based on the pay-as-you-go billing method. For more information, see View the database storage usage.
Purchase a subscription cluster
For information about how to purchase a subscription cluster, see Purchase a subscription cluster.
If you want to change the billing method of a cluster from pay-as-you-go to subscription, see Change the billing method from pay-as-you-go to subscription.
For more information about how to purchase a storage plan, see Purchase a storage plan.