How Azure Databricks prepurchase discount is applied
You can use prepurchased Azure Databricks commit units (DBCU) at any time during the purchase term. Any Azure Databricks usage is deducted from the prepurchased DBCUs automatically.
Unlike VMs, prepurchased units don't expire on an hourly basis. You can use them at any time during the term of the purchase. To get the prepurchase discounts, you don't need to redeploy or assign a prepurchased plan to your Azure Databricks workspaces for the usage.
The prepurchase discount applies only to Azure Databricks unit (DBU) usage. Other charges such as compute, storage, and networking are charged separately.
Prepurchase discount application
Databricks prepurchase applies to all Databricks workloads and tiers. You can think of the prepurchase as a pool of prepaid Databricks commit units. Usage is deducted from the pool, regardless of the workload or tier. Usage is deducted in the following ratio:
|Workload||DBU application ratio — Standard tier||DBU application ratio — Premium tier|
|All Purpose Compute||0.4||0.55|
|Jobs Light Compute||0.07||0.22|
|Delta Live Tables||NA||0.30 (core), 0.38 (pro), 0.54 (advanced)|
|All Purpose Photon||NA||0.55|
For example, when a quantity of Data Analytics – Standard tier is consumed, the prepurchased Databricks commit units is deducted by 0.4 units. When a quantity of Data Engineering Light – Standard tier is used, the prepurchased Databricks commit unit is deducted by 0.07 units.
Note: enabling Photon will increase the DBU count.
Determine plan use
To determine your DBCU plan use, go to the Azure portal > Reservations and select the purchased Databricks plan. Your utilization to-date is shown with any remaining units. For more information about determining your reservation use, see the See reservation usage article.
How discount application shows in usage data
When the prepurchase discount applies to your Databricks usage, on-demand charges appear as zero in the usage data. For more information about reservation costs and usage, see Get Enterprise Agreement reservation costs and usage.
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If you have questions or need help, create a support request.
- To learn how to manage a reservation, see Manage Azure Reservations.
- To learn more about prepurchasing Azure Databricks to save money, see Optimize Azure Databricks costs with a pre-purchase.
- To learn more about Azure Reservations, see the following articles: