Azure SQL Database offers Basic, Standard, Premium, and Premium RS 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||Workload that can tolerate data loss up to 5-minutes due to service failures|
|Uptime SLA||99.99%||99.99%||99.99%||N/A while in preview|
|Backup retention||7 days||35 days||35 days||35 days|
|CPU||Low||Low, Medium, High||Medium, High||Medium|
|IO throughput||Low||Medium||Order of magnitude higher than Standard||Same as Premium|
|IO latency||Higher than Premium||Higher than Premium||Lower than Basic and Standard||Same as Premium|
|Columnstore indexing and in-memory OLTP||N/A||N/A||Supported||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||1 TB|
|Maximum storage size per database*||2 GB||1 TB||1 TB||1 TB|
|Maximum storage size per pool*||156 GB||4 TB||4 TB||1 TB|
|Maximum eDTUs per database||5||3000||4000||1000|
|Maximum eDTUs per pool||1600||3000||4000||1000|
|Maximum number of databases per pool||500||500||100||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: US East2, West US, US Gov Virginia, West Europe, Germany Central, South East Asia, Japan East, Australia East, Canada Central, and Canada East. 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.