Resource limits for elastic pools using the vCore-based purchasing model limits

This article provides the detailed resource limits for Azure SQL Database elastic pools and pooled databases using the vCore-based purchasing model.

For DTU-based purchasing model limits, see SQL Database DTU-based resource limits - elastic pools.

Important

Under some circumstances, you may need to shrink a database to reclaim unused space. For more information, see Manage file space in Azure SQL Database.

You can set the service tier, compute size, and storage amount using the Azure portal, PowerShell, the Azure CLI, or the REST API.

Important

For scaling guidance and considerations, see Scale an elastic pool

Note

The resource limits of individual databases in elastic pools are generally the same as for single databases outside of pools that has the same compute size. For example, the max concurrent workers for an GP_Gen4_1 database is 200 workers. So, the max concurrent workers for a database in a GP_Gen4_1 pool is also 200 workers. Note, the total number of concurrent workers in GP_Gen4_1 pool is 210.

General Purpose service tier: Storage sizes and compute sizes

Important

New Gen4 databases are no longer supported in the Australia East or Brazil South regions.

General Purpose service tier: Generation 4 compute platform (part 1)

Compute size GP_Gen4_1 GP_Gen4_2 GP_Gen4_3 GP_Gen4_4 GP_Gen4_5 GP_Gen4_6
H/W generation 4 4 4 4 4 4
vCores 1 2 3 4 5 6
Memory (GB) 7 14 21 28 35 42
Max number DBs per pool 100 200 500 500 500 500
Columnstore support Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) N/A N/A N/A N/A N/A N/A
Max data size (GB) 512 756 756 1536 1536 1536
Max log size 154 227 227 461 461 461
TempDB size (GB) 32 64 96 128 160 192
Storage type Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage
IO latency (approximate) 5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
Target IOPS (64 KB) 500 1000 1500 2000 2500 3000
Log rate limits (MBps) 4.6875 9.375 14.0625 18.75 23.4375 28.125
Max concurrent workers per pool (requests) * 210 420 630 840 1050 1260
Max concurrent logins per pool * 210 420 630 840 1050 1260
Max allowed sessions 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database 0, 0.25, 0.5, 1 0, 0.25, 0.5, 1, 2 0, 0.25, 0.5, 1...3 0, 0.25, 0.5, 1...4 0, 0.25, 0.5, 1...5 0, 0.25, 0.5, 1...6
Number of replicas 1 1 1 1 1 1
Multi-AZ N/A N/A N/A N/A N/A N/A
Read Scale-out N/A N/A N/A N/A N/A N/A
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

General Purpose service tier: Generation 4 compute platform (part 2)

Compute size GP_Gen4_7 GP_Gen4_8 GP_Gen4_9 GP_Gen4_10 GP_Gen4_16 GP_Gen4_24
H/W generation 4 4 4 4 4 4
vCores 7 8 9 10 16 24
Memory (GB) 49 56 63 70 112 168
Max number DBs per pool 500 500 500 500 500 500
Columnstore support Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) N/A N/A N/A N/A N/A N/A
Max data size (GB) 1536 2048 2048 2048 3584 4096
Max log size (GB) 461 614 614 614 1075 1229
TempDB size (GB) 224 256 288 320 384 384
Storage type Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage
IO latency (approximate) 5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
Target IOPS (64 KB) 3500 4000 4500 5000 7000 7000
Log rate limits (MBps) 32.8125 37.5 37.5 37.5 37.5 37.5
Max concurrent workers per pool (requests) * 1470 1680 1890 2100 3360 5040
Max concurrent logins pool (requests) * 1470 1680 1890 2100 3360 5040
Max allowed sessions 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database 0, 0.25, 0.5, 1...7 0, 0.25, 0.5, 1...8 0, 0.25, 0.5, 1...9 0, 0.25, 0.5, 1...10 0, 0.25, 0.5, 1...10, 16 0, 0.25, 0.5, 1...10, 16, 24
Number of replicas 1 1 1 1 1 1
Multi-AZ N/A N/A N/A N/A N/A N/A
Read Scale-out N/A N/A N/A N/A N/A N/A
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

General Purpose service tier: Generation 5 compute platform (part 1)

Compute size GP_Gen5_2 GP_Gen5_4 GP_Gen5_6 GP_Gen5_8 GP_Gen5_10 GP_Gen5_12 GP_Gen5_14
H/W generation 5 5 5 5 5 5 5
vCores 2 4 6 8 10 12 14
Memory (GB) 10.2 20.4 30.6 40.8 51 61.2 71.4
Max number DBs per pool 100 200 500 500 500 500 500
Columnstore support Yes Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) N/A N/A N/A N/A N/A N/A N/A
Max data size (GB) 512 756 756 1536 1536 1536
Max log size (GB) 154 227 227 461 461 461 461
TempDB size (GB) 64 128 192 256 320 384 384
Storage type Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage
IO latency (approximate) 5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
Target IOPS (64 KB) 1000 2000 3000 4000 5000 6000 7000
Log rate limits (MBps) 4.6875 9.375 14.0625 18.75 23.4375 28.125 32.8125
Max concurrent workers per pool (requests) * 210 420 630 840 1050 1260 1470
Max concurrent logins per pool (requests) * 210 420 630 840 1050 1260 1470
Max allowed sessions 30000 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database 0, 0.25, 0.5, 1, 2 0, 0.25, 0.5, 1...4 0, 0.25, 0.5, 1...6 0, 0.25, 0.5, 1...8 0, 0.25, 0.5, 1...10 0, 0.25, 0.5, 1...12 0, 0.25, 0.5, 1...14
Number of replicas 1 1 1 1 1 1 1
Multi-AZ N/A N/A N/A N/A N/A N/A N/A
Read Scale-out N/A N/A N/A N/A N/A N/A N/A
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

General Purpose service tier: Generation 5 compute platform (part 2)

Compute size GP_Gen5_16 GP_Gen5_18 GP_Gen5_20 GP_Gen5_24 GP_Gen5_32 GP_Gen5_40 GP_Gen5_80
H/W generation 5 5 5 5 5 5 5
vCores 16 18 20 24 32 40 80
Memory (GB) 81.6 91.8 102 122.4 163.2 204 408
Max number DBs per pool 500 500 500 500 500 500 500
Columnstore support Yes Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) N/A N/A N/A N/A N/A N/A N/A
Max data size (GB) 2048 2048 3072 3072 4096 4096 4096
Max log size (GB) 614 614 922 922 1229 1229 1229
TempDB size (GB) 384 384 384 384 384 384 384
Storage type Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage Premium (Remote) Storage
IO latency (approximate) 5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
5-7 ms (write)
5-10 ms (read)
Target IOPS (64 KB) 7000 7000 7000 7000 7000 7000 7000
Log rate limits (MBps) 37.5 37.5 37.5 37.5 37.5 37.5 37.5
Max concurrent workers per pool (requests) * 1680 1890 2100 2520 33600 4200 8400
Max concurrent logins per pool (requests) * 1680 1890 2100 2520 33600 4200 8400
Min/max elastic pool vCore choices per database 0, 0.25, 0.5, 1...16 0, 0.25, 0.5, 1...18 0, 0.25, 0.5, 1...20 0, 0.25, 0.5, 1...20, 24 0, 0.25, 0.5, 1...20, 24, 32 0, 0.25, 0.5, 1...16, 24, 32, 40 0, 0.25, 0.5, 1...16, 24, 32, 40, 80
Number of replicas 1 1 1 1 1 1 1
Multi-AZ N/A N/A N/A N/A N/A N/A N/A
Read Scale-out N/A N/A N/A N/A N/A N/A N/A
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

Business Critical service tier: Storage sizes and compute sizes

Important

New Gen4 databases are no longer supported in the Australia East or Brazil South regions.

Business Critical service tier: Generation 4 compute platform (part 1)

Compute size BC_Gen4_1 BC_Gen4_2 BC_Gen4_3 BC_Gen4_4 BC_Gen4_5 BC_Gen4_6
H/W generation 4 4 4 4 4 4
vCores 1 2 3 4 5 6
Memory (GB) 7 14 21 28 35 42
Max number DBs per pool Only single DBs are supported for this compute size 50 100 100 100 100
Columnstore support Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) 1 2 3 4 5 6
Storage type Local SSD Local SSD Local SSD Local SSD Local SSD Local SSD
Max data size (GB) 650 650 650 650 650 650
Max log size (GB) 195 195 195 195 195 195
TempDB size (GB) 32 64 96 128 160 192
IO latency (approximate) 1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
Target IOPS (64 KB) 5000 10000 15000 20000 25000 30000
Log rate limits (MBps) 10 20 30 40 50 60
Max concurrent workers per pool (requests) * 210 420 630 840 1050 1260
Max concurrent logins per pool (requests) * 210 420 630 840 1050 1260
Max allowed sessions 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database N/A 0, 0.25, 0.5, 1, 2 0, 0.25, 0.5, 1...3 0, 0.25, 0.5, 1...4 0, 0.25, 0.5, 1...5 0, 0.25, 0.5, 1...6
Number of replicas 4 4 4 4 4 4
Multi-AZ Yes Yes Yes Yes Yes Yes
Read Scale-out Yes Yes Yes Yes Yes Yes
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

Business Critical service tier: Generation 4 compute platform (part 2)

Compute size BC_Gen4_7 BC_Gen4_8 BC_Gen4_9 BC_Gen4_10 BC_Gen4_16 BC_Gen4_24
H/W generation 4 4 4 4 4 4
vCores 7 8 9 10 16 24
Memory (GB) 81.6 91.8 102 122.4 163.2 204
Max number DBs per pool 100 100 100 100 100 100
Columnstore support N/A N/A N/A N/A N/A N/A
In-memory OLTP storage (GB) 7 8 9.5 11 20 36
Storage type Local SSD Local SSD Local SSD Local SSD Local SSD Local SSD
Max data size (GB) 650 650 650 650 1024 1024
Max log size (GB) 195 195 195 195 307 307
TempDB size (GB) 224 256 288 320 384 384
IO latency (approximate) 1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
Target IOPS (64 KB) 35000 40000 45000 50000 80000 120000
Log rate limits (MBps) 70 80 80 80 80 80
Max concurrent workers per pool (requests) * 1470 1680 1890 2100 3360 5040
Max concurrent logins per pool (requests) * 1470 1680 1890 2100 3360 5040
Max allowed sessions 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database 0, 0.25, 0.5, 1...7 0, 0.25, 0.5, 1...8 0, 0.25, 0.5, 1...9 0, 0.25, 0.5, 1...10 0, 0.25, 0.5, 1...10, 16 0, 0.25, 0.5, 1...10, 16, 24
Number of replicas 4 4 4 4 4 4
Multi-AZ Yes Yes Yes Yes Yes Yes
Read Scale-out Yes Yes Yes Yes Yes Yes
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

Business Critical service tier: Generation 5 compute platform (part 1)

Compute size BC_Gen5_2 BC_Gen5_4 BC_Gen5_6 BC_Gen5_8 BC_Gen5_10 BC_Gen5_12 BC_Gen5_14
H/W generation 5 5 5 5 5 5 5
vCores 2 4 6 8 10 12 14
Memory (GB) 10.2 20.4 30.6 40.8 51 61.2 71.4
Max number DBs per pool Only single DBs are supported for this compute size 50 100 100 100 100 100
Columnstore support Yes Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) 1.571 3.142 4.713 6.284 8.655 11.026 13.397
Max data size (GB) 1024 1024 1536 1536 1536 3072 3072
Max log size (GB) 307 307 307 461 461 922 922
TempDB size (GB) 64 128 192 256 320 384 384
Storage type Local SSD Local SSD Local SSD Local SSD Local SSD Local SSD Local SSD
IO latency (approximate) 1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
Target IOPS (64 KB) 5000 10000 15000 20000 25000 30000 35000
Log rate limits (MBps) 15 30 45 60 75 90 105
Max concurrent workers per pool (requests) * 210 420 630 840 1050 1260 1470
Max concurrent logins per pool (requests) * 210 420 630 840 1050 1260 1470
Max allowed sessions 30000 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database N/A 0, 0.25, 0.5, 1...4 0, 0.25, 0.5, 1...6 0, 0.25, 0.5, 1...8 0, 0.25, 0.5, 1...10 0, 0.25, 0.5, 1...12 0, 0.25, 0.5, 1...14
Number of replicas 4 4 4 4 4 4 4
Multi-AZ Yes Yes Yes Yes Yes Yes
Read Scale-out Yes Yes Yes Yes Yes Yes Yes
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

Business Critical service tier: Generation 5 compute platform (part 2)

Compute size BC_Gen5_16 BC_Gen5_18 BC_Gen5_20 BC_Gen5_24 BC_Gen5_32 BC_Gen5_40 BC_Gen5_80
H/W generation 5 5 5 5 5 5 5
vCores 16 18 20 24 32 40 80
Memory (GB) 81.6 91.8 102 122.4 163.2 204 408
Max number DBs per pool 100 100 100 100 100 100 100
Columnstore support Yes Yes Yes Yes Yes Yes Yes
In-memory OLTP storage (GB) 15.768 18.139 20.51 25.252 37.936 52.22 131.64
Max data size (GB) 3072 3072 3072 4096 4096 4096 4096
Max log size (GB) 922 922 922 1229 1229 1229 1229
TempDB size (GB) 384 384 384 384 384 384 384
Storage type Local SSD Local SSD Local SSD Local SSD Local SSD Local SSD Local SSD
IO latency (approximate) 1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
1-2 ms (write)
1-2 ms (read)
Target IOPS (64 KB) 40000 45000 50000 60000 80000 100000 200000
Log rate limits (MBps) 120 120 120 120 120 120 120
Max concurrent workers per pool (requests) * 1680 1890 2100 2520 3360 4200 8400
Max concurrent logins per pool (requests) * 1680 1890 2100 2520 3360 4200 8400
Max allowed sessions 30000 30000 30000 30000 30000 30000 30000
Min/max elastic pool vCore choices per database 0, 0.25, 0.5, 1...16 0, 0.25, 0.5, 1...18 0, 0.25, 0.5, 1...20 0, 0.25, 0.5, 1...20, 24 0, 0.25, 0.5, 1...20, 24, 32 0, 0.25, 0.5, 1...20, 24, 32, 40 0, 0.25, 0.5, 1...20, 24, 32, 40, 80
Number of replicas 4 4 4 4 4 4 4
Multi-AZ Yes Yes Yes Yes Yes Yes Yes
Read Scale-out Yes Yes Yes Yes Yes Yes Yes
Included backup storage 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size 1X DB size

* For the max concurrent workers (requests) for any individual database, see Single database resource limits. For example, if the elastic pool is using Gen5 and its max vCore per database is 2, then the max concurrent workers is 200. If max vCore per database is 0.5, then the max concurrent workers is 50 since on Gen5 there are a max of 100 concurrent workers per vcore. For other max vCore settings per database that are less 1 vCore or less, the number of max concurrent workers is similarly rescaled.

If all vCores of an elastic pool are busy, then each database in the pool receives an equal amount of compute resources to process queries. The SQL Database service provides resource sharing fairness between databases by ensuring equal slices of compute time. Elastic pool resource sharing fairness is in addition to any amount of resource otherwise guaranteed to each database when the vCore min per database is set to a non-zero value.

Database properties for pooled databases

The following table describes the properties for pooled databases.

Property Description
Max vCores per database The maximum number of vCores that any database in the pool may use, if available based on utilization by other databases in the pool. Max vCores per database is not a resource guarantee for a database. This setting is a global setting that applies to all databases in the pool. Set max vCores per database high enough to handle peaks in database utilization. Some degree of over-committing is expected since the pool generally assumes hot and cold usage patterns for databases where all databases are not simultaneously peaking.
Min vCores per database The minimum number of vCores that any database in the pool is guaranteed. This setting is a global setting that applies to all databases in the pool. The min vCores per database may be set to 0, and is also the default value. This property is set to anywhere between 0 and the average vCores utilization per database. The product of the number of databases in the pool and the min vCores per database cannot exceed the vCores per pool.
Max storage per database The maximum database size set by the user for a database in a pool. Pooled databases share allocated pool storage, so the size a database can reach is limited to the smaller of remaining pool storage and database size. Max database size refers to the maximum size of the data files and does not include the space used by log files.

Next steps