Resource limits for single databases using the DTU purchasing model - Azure SQL Database
Applies to: Azure SQL Database
This article provides the detailed resource limits for Azure SQL Database single databases using the DTU purchasing model.
- For DTU purchasing model limits for single databases on a server, see Overview of resource limits on a server.
- For DTU purchasing model resource limits for Azure SQL Database, see DTU resource limits single databases and DTU resource limits elastic pools.
- For vCore resource limits, see vCore resource limits - Azure SQL Database and vCore resource limits - elastic pools.
- For more information regarding the different purchasing models, see Purchasing models and service tiers.
Each read-only replica has its own resources such as DTUs, workers, and sessions. Each read-only replica is subject to the resource limits detailed later in this article.
Single database: Storage sizes and compute sizes
The following tables show the resources available for a single database at each service tier and compute size. You can set the service tier, compute size, and storage amount for a single database using:
Important
For scaling guidance and considerations, see Scale a single database
Basic service tier
Compute size | Basic |
---|---|
Max DTUs | 5 |
Included storage (GB) | 2 |
Max storage (GB) | 2 |
Max in-memory OLTP storage (GB) | N/A |
Max concurrent workers | 30 |
Max concurrent logins | 30 |
Max concurrent external connections 1 | 3 |
Max concurrent sessions | 300 |
1 See External Connections for additional details on what counts as an external connection.
Important
The Basic service tier provides less than one vCore (CPU). For resource-intensive workloads, a service tier of S3 or greater is recommended.
Database restore operations can be resource-intensive and may require a service objective of S3 or greater. Once restored, a database can be scaled down to a lower service objective if required.
Regarding data storage, the Basic service tier is placed on Standard Page Blobs. Standard Page Blobs use hard disk drive (HDD)-based storage media and are best suited for development, testing, and other infrequently accessed workloads that are less sensitive to performance variability.
Standard service tier
Compute size | S0 | S1 | S2 | S3 |
---|---|---|---|---|
Max DTUs | 10 | 20 | 50 | 100 |
Included storage (GB) 1 | 250 | 250 | 250 | 250 |
Max storage (GB) | 250 | 250 | 250 | 1024 |
Max in-memory OLTP storage (GB) | N/A | N/A | N/A | N/A |
Max concurrent workers | 60 | 90 | 120 | 200 |
Max concurrent logins | 60 | 90 | 120 | 200 |
Max concurrent external connections 2 | 6 | 9 | 12 | 20 |
Max concurrent sessions | 600 | 900 | 1200 | 2400 |
1 See SQL Database pricing options for details on additional cost incurred due to any extra storage provisioned.
2 See External Connections for additional details on what counts as an external connection.
Important
The Standard S0, S1 and S2 tiers provide less than one vCore (CPU). For resource-intensive workloads, a service tier of S3 or greater is recommended.
Restoration operations can be resource-intensive and often require a service tier of S3 or greater.
Regarding data storage, the Standard S0 and S1 service tiers are placed on Standard Page Blobs. Standard Page Blobs use hard disk drive (HDD)-based storage media and are best suited for development, testing, and other infrequently accessed workloads that are less sensitive to performance variability.
Standard service tier (continued)
Compute size | S4 | S6 | S7 | S9 | S12 |
---|---|---|---|---|---|
Max DTUs | 200 | 400 | 800 | 1600 | 3000 |
Included storage (GB) 1 | 250 | 250 | 250 | 250 | 250 |
Max storage (GB) | 1024 | 1024 | 1024 | 1024 | 1024 |
Max in-memory OLTP storage (GB) | N/A | N/A | N/A | N/A | N/A |
Max concurrent workers | 400 | 800 | 1600 | 3200 | 6000 |
Max concurrent logins | 400 | 800 | 1600 | 3200 | 6000 |
Max concurrent external connections 2 | 40 | 80 | 150 | 150 | 150 |
Max concurrent sessions | 4800 | 9600 | 19200 | 30000 | 30000 |
1 See SQL Database pricing options for details on additional cost incurred due to any extra storage provisioned.
2 See External Connections for additional details on what counts as an external connection.
Premium service tier
Compute size | P1 | P2 | P4 | P6 | P11 | P15 |
---|---|---|---|---|---|---|
Max DTUs | 125 | 250 | 500 | 1000 | 1750 | 4000 |
Included storage (GB) 1 | 500 | 500 | 500 | 500 | 4096 2 | 4096 2 |
Max storage (GB) | 1024 | 1024 | 1024 | 1024 | 4096 2 | 4096 2 |
Max in-memory OLTP storage (GB) | 1 | 2 | 4 | 8 | 14 | 32 |
Max concurrent workers | 200 | 400 | 800 | 1600 | 2800 | 6400 |
Max concurrent logins | 200 | 400 | 800 | 1600 | 2800 | 6400 |
Max concurrent external connections 3 | 20 | 40 | 80 | 150 | 150 | 150 |
Max concurrent sessions | 30000 | 30000 | 30000 | 30000 | 30000 | 30000 |
1 See SQL Database pricing options for details on additional cost incurred due to any extra storage provisioned.
2 From 1024 GB up to 4096 GB in increments of 256 GB.
3 See External Connections for additional details on what counts as an external connection.
Important
More than 1 TB of storage in the Premium tier is currently available in all regions except: China East, China North, Germany Central, and Germany Northeast. In these regions, the storage max in the Premium tier is limited to 1 TB. For more information, see P11-P15 current limitations.
Note
For additional information on storage limits in the Premium service tier, see Storage space governance.
Tempdb sizes
The following table lists tempdb
sizes for single databases in Azure SQL Database:
Service-level objective | Maximum tempdb data file size (GB) |
Number of tempdb data files |
Maximum tempdb data size (GB) |
---|---|---|---|
Basic | 13.9 | 1 | 13.9 |
S0 | 13.9 | 1 | 13.9 |
S1 | 13.9 | 1 | 13.9 |
S2 | 13.9 | 1 | 13.9 |
S3 | 32 | 1 | 32 |
S4 | 32 | 2 | 64 |
S6 | 32 | 3 | 96 |
S7 | 32 | 6 | 192 |
S9 | 32 | 12 | 384 |
S12 | 32 | 12 | 384 |
P1 | 13.9 | 12 | 166.7 |
P2 | 13.9 | 12 | 166.7 |
P4 | 13.9 | 12 | 166.7 |
P6 | 13.9 | 12 | 166.7 |
P11 | 13.9 | 12 | 166.7 |
P15 | 13.9 | 12 | 166.7 |
Next steps
- For vCore resource limits for a single database, see resource limits for single databases using the vCore purchasing model
- For vCore resource limits for elastic pools, see resource limits for elastic pools using the vCore purchasing model
- For DTU resource limits for elastic pools, see resource limits for elastic pools using the DTU purchasing model
- For resource limits for managed instances in Azure SQL Managed Instance, see SQL Managed Instance resource limits.
- For information about general Azure limits, see Azure subscription and service limits, quotas, and constraints.
- For information about resource limits on a logical SQL server, see overview of resource limits on a logical SQL server for information about limits at the server and subscription levels.