PolarDB for MySQL provides storage plans to reduce the storage costs of your clusters.
Storage plans
The storage capacity of PolarDB 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 of each PolarDB cluster is billed based on the data volume and retention period of time. 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 various costs related to storage usage in PolarDB, including cluster storage, level-1 backup storage beyond the free quota, level-2 backup storage, log backup storage, cold data storage, and Serverless storage. Storage plans can reduce costs. If you select a larger capacity and a longer duration for the storage plan that you purchase, you can receive a higher discount.
For example, a monthly storage plan costs 10% to 45% less than using the pay-as-you-go method for the storage of a cluster. The longer the duration of the storage plan, the higher the cost reduction. If you purchase annual storage plans, you can save an additional 15% off the monthly price.
Applicable storage and offset rules
Storage plans can be used to offset various costs related to storage usage in PolarDB, including cluster storage, level-1 backup storage beyond the free quota, level-2 backup storage, log backup storage, cold data storage, and Serverless storage.
Offset the fees of the storage capacity of a pay-as-you-go PolarDB Enterprise Edition cluster. For more information, see Billing rules for storage capacity.
NoteStorage plans can offset only the storage that uses the pay-as-you-go billing method and cannot offset storage that uses the subscription billing method.
Storage plans can also be used to offset the fees of the Serverless feature for a serverless cluster and a cluster with fixed specifications.
After your storage plans are exhausted, you are charged for the excess storage on a pay-as-you-go basis.
Storage type
Offset factor
Storage capacity offset by a 1-GB storage plan (regions in the Chinese mainland)
Storage capacity offset by a 1-GB storage plan (regions outside the Chinese mainland)
PSL4 (Hot standby storage cluster enabled)
0.65
1.54 GB
1.54 GB
PSL4 (Hot standby storage cluster disabled)
0.325
3.08 GB
3.08 GB
PSL5 (Hot standby storage cluster enabled)
1
1 GB
1 GB
PSL5 (Hot standby storage cluster disabled)
0.5
2 GB
2 GB
For example, for a PSL4 cluster in a region of the Chinese mainland with hot standby storage cluster enabled, a 50-GB storage plan can be used to deduct a storage capacity of 76.92 GB (1/0.65 × 50). Excess storage usage over 76.92 GB is charged on a pay-as-you-go basis.
Offset the level-1 backup storage fees of a PolarDB Enterprise Edition cluster. For more information, see Billing rules of backup storage that exceeds the free quota.
Region type
Offset factor
Level-1 backup storage capacity offset by a 1-GB storage plan
Regions in the Chinese mainland (PSL4)
0.41
1/0.41=2.44 GB
Regions in the Chinese mainland (PSL5)
0.617
1/0.617=1.62 GB
Regions outside the Chinese mainland (PSL4)
0.41
1/0.41=2.44 GB
Regions outside the Chinese mainland (PSL5)
0.617
1/0.617=1.62 GB
For example, you purchase a storage plan with a capacity of 100 GB and 50 GB is left after you offset the storage space (PSL5). Your cluster uses 50 GB of storage for level-1 backups (outside the free quota) in a Chinese mainland region. In this case, the storage plan automatically uses 31.25 GB (50/1.6=31.25) to offset the backup storage. As a result, the storage plan has 18.75 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the level-1 backups, you are charged for the excess storage usage on a pay-as-you-go basis.
Offset the level-2 backup storage fees of a PolarDB Enterprise Edition. For more information, see Billing rules of backup storage that exceeds the free quota.
Region type
Offset factor
Level-2 backup storage capacity offset by a 1-GB storage plan
Regions in the Chinese mainland
0.043
1/0.043=23.26 GB
Regions outside the Chinese mainland
0.054
1/0.054=18.52 GB
For example, you purchase a storage plan with a capacity of 100 GB, and 50 GB is left after it offsets the data storage usage. Your cluster uses 50 GB of storage for level-2 backups in a Chinese mainland region. In this case, the storage plan automatically uses 2.15 GB (50/23.26) to offset the backup storage usage and the storage plan has 47.85 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the level-2 backups, you are charged for the excess storage usage on a pay-as-you-go basis.
Offset the log backup storage fees of a PolarDB Enterprise Edition cluster. For more information, see Billing rules of backup storage that exceeds the free quota.
Region type
Offset factor
Log backup storage capacity offset by a 1-GB storage plan
Regions in the Chinese mainland
0.043
1/0.043=23.26 GB
Regions outside the Chinese mainland
0.054
1/0.054=18.52 GB
For example, you purchase a storage plan with a capacity of 100 GB, and 50 GB is left after it offsets the data storage usage. Your cluster uses 50 GB of storage for log backups in a Chinese mainland region. In this case, the storage plan automatically uses 2.15 GB (50/23.26) to offset the backup storage usage and the storage plan has 47.85 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the log backups, you are charged for the excess storage usage on a pay-as-you-go basis.
Offset the storage fees of cold data archived to Object Storage Service (OSS) for a PolarDB Enterprise Edition cluster. For more information about cold data archiving, see Overview.
Region type
Offset factor
OSS storage capacity offset by a 1-GB storage plan
Regions in the Chinese mainland
0.045
1/0.045=22.22 GB
Regions outside the Chinese mainland
0.045
1/0.045=22.22 GB
For example, you purchase a storage plan with a capacity of 100 GB, and 50 GB is left after it offsets the data storage usage. The cold data of your cluster occupies 50 GB of OSS storage space in a Chinese mainland region. In this case, the storage plan automatically uses 2.25 GB (50/22.22) to offset the backup usage of the cold data and the storage plan has 47.75 GB of capacity left.
If the remaining capacity of the storage plan is insufficient to offset the cold data storage, you are charged for additional storage space on a pay-as-you-go basis.
Offset order
Storage spaces are offset based on the following order:
For PolarDB Enterprise Edition clusters: cluster storage for PSL4 and PSL5 > level-1 backup storage beyond the free quota > OSS storage of cold data > level-2 backup storage > log backup storage. If multiple clusters have the same deduction priority, the clusters are deducted based on the creation time. The cluster that is created earlier than other clusters is deducted first.
Apply storage plans
PolarDB provides two billing methods for compute nodes: pay-as-you-go and subscription. The price of your cluster varies based on the used billing method. You can apply storage plans to compute nodes that use the two billing methods.
Pricing of storage plans
This section describes the price comparison of different offset capacity under the two purchase schemes of unused storage plans and monthly storage plans.
Capacity (GB) | Regions in the Chinese mainland (USD/month) (1.7% to 47.0% off compared with the pay-as-you-go billing method) | Hong Kong (China) and regions outside China (USD/month) (1.6% to 46.6% off compared with the pay-as-you-go billing method) |
50 | 28 (No discount) | 31 (No discount) |
100 | 55 (approximately 1.7% off) | 61 (approximately 1.6% off) |
200 | 109 (approximately 2.7% off) | 121 (approximately 2.4% off) |
300 | 163 (approximately 3% off) | 182 (approximately 2.6% off) |
500 | 271 (approximately 3.2% off) | 302 (approximately 2.6% off) |
1,000 | 490 (approximately 12.5% off) | 550 (approximately 11.3% off) |
2,000 | 980 (approximately 12.5% off) | 1,090 (approximately 12.1% off) |
3,000 | 1,210 (approximately 28.0% off) | 1,340 (approximately 28.0% off) |
5,000 | 2,020 (approximately 28.0% off) | 2,230 (approximately 28.1% off) |
10,000 | 3,260 (approximately 41.8% off) | 3,630 (approximately 41.5% off) |
20,000 | 6,510 (approximately 41.9% off) | 7,250 (approximately 41.5% off) |
30,000 | 9,760 (approximately 42.0% off) | 10,870 (approximately 41.5% off) |
50,000 | 14,860 (approximately 47.0% off) | 16,550 (approximately 46.6% off) |
100,000 | 29,720 (approximately 47.0% off) | 33,110 (approximately 46.6% off) |
200,000 | 59,440 (approximately 47.0% off) | 66,220 (approximately 46.6% off) |
Purchase a storage plan
For more information about the discount rates of storage plans and about how to purchase storage plans, see Purchase a storage plan.
Storage plans can be used by all PolarDB clusters in the regions that are specified by the Plan Type parameter. You can select Chinese Mainland or Outside Chinese Mainland for this parameter.
If the capacity of your storage plan is insufficient, you can purchase an additional storage plan or upgrade the storage plan. However, you cannot downgrade storage plans that you purchase. For more information about how to upgrade a storage plan, see Upgrade a storage plan.
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, you have created three PolarDB clusters that each have 400 GB of storage. If you purchase a storage plan of 1,000 GB and these clusters share the storage plan, the storage resources used in excess of 200 GB are billed on a pay-as-you-go basis. For more information, see View the database storage usage.