What are Azure SQL Database service tiers?
Azure SQL Database offers Basic, Standard, and Premium service tiers for both single databases and elastic pools. Service tiers are primarily differentiated by a range of performance level and storage size choices, and price. All service tiers provide flexibility in changing performance level and storage size. Single databases and elastic pools are billed hourly based on service tier, performance level, and storage size.
Choosing a service tier
Choosing a service tier depends primarily on business continuity, storage, and performance requirements.
|Target workload||Development and production||Development and production||Development and production|
|Backup retention||7 days||35 days||35 days|
|CPU||Low||Low, Medium, High||Medium, High|
|IO throughput||Low||Medium||Order of magnitude higher than Standard|
|IO latency||Higher than Premium||Higher than Premium||Lower than Basic and Standard|
|Columnstore indexing and in-memory OLTP||N/A||N/A||Supported|
Performance level and storage size limits
Performance levels are expressed in terms of Database Transaction Units (DTUs) for single databases and elastic Database Transaction Units (eDTUs) for elastic pools. For more on DTUs and eDTUs, see What are DTUs and eDTUs?
|Maximum storage size*||2 GB||1 TB||4 TB|
|Maximum storage size per database*||2 GB||1 TB||1 TB|
|Maximum storage size per pool*||156 GB||4 TB||4 TB|
|Maximum eDTUs per database||5||3000||4000|
|Maximum eDTUs per pool||1600||3000||4000|
|Maximum number of databases per pool||500||500||100|
* Storage sizes greater than the amount of included storage are in preview and extra costs apply. For details, see SQL Database pricing.
* In the Premium tier, more than 1 TB of storage is currently available in the following regions: Australia East, Australia Southeast, Brazil South, Canada Central, Canada East, Central US, France Central, Germany Central, Japan East, Japan West, Korea Central, North Central US, North Europe, South Central US, South East Asia, UK South, UK West, US East2, West US, US Gov Virginia, and West Europe. See P11-P15 Current Limitations.
For details on specific performance levels and storage size choices available, see SQL Database resource limits.
- Learn about Single database resources.
- Learn about elastic pools, see Elastic pools.
- Learn about Azure Subscription and Service Limits, Quotas, and Constraints
- Learn more about DTUs and eDTUs.
- Learn about monitoring DTU usage, see Monitoring and performance tuning.