PolarDB allows you to use the backup and restoration features free of charge. However, backup files consume storage space. You are charged when you consume more backup space than the free quota. This topic describes the billing rules for PolarDB backup storage that exceeds the free quota.
Billing rules for backup storage
Free quota
PolarDB offers a free storage quota for backup files. After this quota is exhausted, for single-region backup on PolarDB, you are charged based on the storage capacity and retention period of backup files (data and logs). For cross-region backup on PolarDB, you are charged based on the storage capacity and retention period of backup files (data and logs) and the network traffic consumed by cross-region backup.
Backup type | Free quota | |
Data backup | Level-1 backup | Database storage usage × 50% For information about how to view the database storage usage, see View the database storage usage. |
Level-2 backup | N/A | |
Log backup | 100 GB | |
You can enable the storage compression feature on a cluster of PolarDB Enterprise Edition Cluster Edition. For more information, see Enable the storage compression feature.
Billing rules
Storage types include level-1 backup, level-2 backup, and log backup based on backup types. Prices vary with different storage types.
Free storage quota for level-1 backup is database storage usage × 50%. After the free quota is exhausted, you are charged by PolarDB for the amount of additional storage space consumed by the backup and the length of time for which the backup is retained. The following table describes the prices.
Storage type
Region in the Chinese mainland
Region outside the Chinese mainland
Billing method
PSL5
USD 0.000464 per GB-hour
USD 0.000650 per GB-hour
Storage fee per hour = (Total size of level-1 backup - Free quota) × Unit price per hour
For example, a PolarDB cluster deployed in the Chinese mainland uses the PSL5 storage type. If the total size of level-1 backup (snapshots) is 700 GB and the database storage usage is 1,000 GB, the storage fee per hour is USD 0.0928.
The fee is calculated based on the following formula: [700 GB - (1,000 GB × 50%)] × USD 0.000464/GB = USD 0.0928.
NoteFor more information about how to view the size of level-1 backup, see FAQ.
PSL4
USD 0.0003 per GB-hour
USD 0.000433 per GB-hour
NoteAfter the free quota is consumed, you are charged for additional storage space on a pay-as-you-go basis. To reduce the costs of level-1 backup, we recommend that you use storage plans, which are cost-effective. For more information, see Billing rules for backup storage that exceeds the free quota.
No free storage quota is offered for level-2 backup. Level-2 backup can be stored in the same region as the PolarDB cluster or in a different region. For single-region backup on PolarDB, you are charged based on the storage capacity and retention period of backup files (data and logs). For cross-region backup on PolarDB, you are charged based on the storage capacity and retention period of backup files (data and logs) and the network traffic consumed by cross-region backup. The following table describes the prices.
Billing rules for single-region backup
Region in the Chinese mainland
Region outside the Chinese mainland
Billing method
USD 0.0000325 per GB-hour
USD 0.0000455 per GB-hour
Storage fee per hour = Total size of level-2 backup × Unit price per hour
For example, a PolarDB for MySQL cluster is deployed in the Chinese mainland. If the total size of level-2 backup is 1,000 GB, the storage fee per hour is USD 0.0325.
The fee is calculated based on the following formula: 1,000 GB × USD 0.0000325/GB = USD 0.0325.
Billing rules for cross-region backup
Billable item
Region in the Chinese mainland
Region outside the Chinese mainland
Billing method
Backup storage
USD 0.0000325 per GB-hour
USD 0.0000455 per GB-hour
Storage fee per hour = Total size of level-2 backup × Unit price per hour + Network traffic price for cross-region backup
For example, a PolarDB cluster is deployed in the Chinese mainland. If the total size of level-2 backup is 1,000 GB and the network traffic consumed by the cross-region backup is 500 MB, the storage fee per hour is USD 0.0691.
The fee is calculated based on the following formula: 1,000 GB × USD 0.0000325/GB + 500 MB/1024 × USD 0.075/GB = USD 0.0691.
Network traffic
For more information about fees for network traffic consumed by cross-region backup, see Network traffic fees.
NoteCross-region backup is billed on a daily basis. In this document, it is converted to the hourly price.
Fees for cross-region backup are recorded in DBS bills.
A free quota of 100 GB is offered for log backup. Log backup can be stored in the same region as the PolarDB cluster or in a different region. After this quota is exhausted, for single-region backup on PolarDB, you are charged based on the storage capacity and retention period of backup files (data and logs). For cross-region backup on PolarDB, you are charged based on the storage capacity and retention period of backup files (data and logs) and the network traffic consumed by cross-region backup. The following table describes the prices.
Billing rules for single-region backup
Region in the Chinese mainland
Region outside the Chinese mainland
Billing method
USD 0.0000325 per GB-hour
USD 0.0000455 per GB-hour
Storage fee per hour = (Total physical storage of log backup - 100 GB) × Unit price per hour
For example, if the total size of log backup is 1,000 GB, the storage fee per hour is USD 0.02925.
The fee is calculated based on the following formula: (1,000 GB - 100 GB) × USD 0.0000325/GB = USD 0.02925.
Billing rules for cross-region backup
Billable item
Region in the Chinese mainland
Region outside the Chinese mainland
Billing method
Backup storage
USD 0.0000325 per GB-hour
USD 0.0000455 per GB-hour
Storage fee per hour = (Total physical storage of log backup - 100 GB) × Unit price per hour + Network traffic price for cross-region backup
For example, a PolarDB cluster is deployed in the Chinese mainland. If the total size of log backup is 1,000 GB and the network traffic consumed by the cross-region backup is 500 MB, the storage fee per hour is USD 0.0659.
The fee is calculated based on the following formula: (1,000 GB - 100 GB) × USD 0.0000325/GB + 500 MB/1024 × USD 0.075/GB = USD 0.0659
Network traffic
For more information about fees for network traffic consumed by cross-region backup, see Network traffic fees.
NoteCross-region backup is billed on a daily basis. In this document, it is converted to the hourly price.
Fees for cross-region backup are recorded in DBS bills.
If you modify data after the snapshots of your cluster are created, the amount of snapshot backup increases. In this case, you are charged for the additional backup. If data is modified during defragmentation, the number of snapshot backup increases.
For example, if your database has 100 GB of data and you modify 10 GB of the data after a snapshot is created:
You are charged for 100 GB of data storage and 10 GB of snapshot storage.
If you choose to retain the snapshots when you delete your database, you are charged for 100 GB of snapshot storage.
Offset rules for storage plans
Use storage plans to offset level-1 backup storage fees
A storage plan can be used to offset the storage space exceeding the free quota for level-1 backups. If the capacity of the storage plan is insufficient to offset the level-1 backup storage space, you are charged for additional storage space on a pay-as-you-go basis.
The following table lists the ratios.
Region type | Offset ratio | 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.
For more information about storage plans, see FAQ about billing of storage plans.
Use storage plans to offset level-2 backup storage fees
A storage plan can be used to offset the storage space for level-2 backups. If the capacity of the storage plan is insufficient to offset the level-2 backup storage space, you are charged for additional storage space on a pay-as-you-go basis.
The following table lists the ratios.
Region type | Offset ratio | 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.
For more information about storage plans, see FAQ about billing of storage plans.
Use storage plans to offset log backup storage fees
A storage plan can be used to offset the storage space for log backups. If the capacity of the storage plan is insufficient to offset the log backup storage space, you are charged for additional storage space on a pay-as-you-go basis.
The following table lists the ratios.
Region type | Offset ratio | 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.
For more information about storage plans, see FAQ about billing of storage plans.
Reduce the charges for backup storage usage
You cannot download PolarDB backup files to your PC. To reduce backup fees, you can use one of the following methods:
Select an appropriate backup frequency: In the Backup Policy Settings dialog box, set Backup Frequency to an appropriate value.
NoteLow frequency of level-2 backup can reduce backup costs.
Shorten the retention period of level-1 backup: In the Backup Policy Settings dialog box, set Level-1 Backup in the Data Backup Retention Period section.
Purchase storage plans to offset level-1 backup fees: You can use storage plans to offset the fees generated by level-1 backup, which are cost-effective. For more information, see Billing rules for backup storage that exceeds the free quota.