What are Azure SQL Database service tiers

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.

Basic Standard Premium Premium RS
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?.

Single databases

Basic Standard Premium Premium RS
Maximum storage size* 2 GB 1 TB 4 TB 1 TB
Maximum DTUs 5 3000 4000 1000

Elastic pools

Basic Standard Premium Premium RS
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.

Next steps