If you use the subscription billing method, you must pay for the compute nodes when you create clusters. However, you are charged for the used storage on an hourly basis. Fees for the storage that you use are deducted from your account on an hourly basis. Therefore, pay-as-you-go bills are still generated when you use the subscription billing method.
If your workloads are heavy, infrequently change, and have small fluctuations, we recommend that you purchase subscription clusters. Compared with the pay-as-you-go method, the subscription billing method is more cost-effective when a large volume of storage is required.
Together with storage plans
The storage capacity of PolarDB is automatically scaled in or out based on the amount of stored data. You do not need to manually specify the storage capacity. You are charged for only the used storage. We recommend that you purchase PolarDB storage plans if you want to store a large volume of data. This reduces the storage costs.
You are charged based on the data volume and retention period. If you require a large storage capacity, such as 1,000 GB or more, we recommend that you use this billing method together with storage plans. Greater discounts are offered on storage plans with larger capacities.
- You can select the following types of storage plans: storage plans that apply to regions inside mainland China, and storage plans that apply to China (Hong Kong) and regions outside China. You can purchase only one storage plan for each type.
- A storage plan can be shared by multiple clusters. A storage plan can be used by all the clusters in the regions that are specified by the Plan Type parameter. You can specify mainland China or China (Hong Kong) and regions outside China as the value of the parameter.
- If the capacity of your storage plan is insufficient, you can upgrade the storage plan. However, storage plans cannot be downgraded.
- You are charged for the extra storage that is not covered by the storage plan on a pay-as-you-go basis.
Assume that you have three PolarDB clusters and each cluster requires 400 GB of storage. If you purchase a storage plan of 1,000 GB and these clusters share the storage plan, you are charged for the extra 200 GB of storage based on the pay-as-you-go billing method. For more information, see View the database storage usage.