Service Concurrency
The consumer groups of the predefined service names provide different levels of performance and concurrency.
Picking one of the predefined services provides concurrency values that work well for most applications. In cases where selecting one of the default services does not meet your application’s performance needs, you can use the MEDIUM service and modify the concurrency limit. For example, when you run single-user benchmarks, you can set the concurrency limit of the MEDIUM service to 1 in order to obtain the highest degree of parallelism (DOP).
In this topic, the "number of ECPUs" is the ECPU count shown in the Oracle Cloud Infrastructure Console. Likewise, if your database uses the OCPU compute model, the "number of OCPUs" is the OCPU count.
Note:
OCPU is a legacy billing metric and has been retired on Autonomous Database. ECPUs are the replacement billing metric for all new and existing Autonomous Database deployments. See Oracle Support Document 2998742.1 for more information.Service Concurrency Limits for ECPU Compute Model
The
tnsnames.ora file provided with the credentials zip file contains
five database service names identifiable as tpurgent, tp, high, medium, and low. These
services are available for each Autonomous Database workload type.
The following shows the details for the default number of concurrent statements for each connection service.
Note:
The values in this table apply when the number of ECPUs is equal to or greater than 4.When the number of ECPUs is 2, all services use the concurrency limit 150. When the number of ECPUs is 3, all services use the concurrency limit 225 (this applies for Compute auto scaling enabled or disabled).
| Database Service Name | Concurrent Statements with Compute Auto Scaling Disabled | Concurrent Statements with Compute Auto Scaling Enabled |
|---|---|---|
|
|
75 × number of ECPUs |
75 × number of ECPUs |
|
|
75 × number of ECPUs |
75 × number of ECPUs |
|
|
3 |
9 |
|
|
0.25125 × number of ECPUs
A decimal result is truncated. |
0.75375 × number of ECPUs
A decimal result is truncated. |
|
|
75 × number of ECPUs |
75 × number of ECPUs |
See Database Service Names for Autonomous Database and Change MEDIUM Service Concurrency Limit (ECPU Compute Model) more information.
Service Concurrency Limits for OCPU Compute Model
The
tnsnames.ora file provided with the credentials zip file contains
five database service names identifiable as tpurgent, tp, high, medium, and low.
The following shows the details for the default number of concurrent statements for each connection service for OCPU compute model.
Note:
The values in this table apply when the number of OCPUs is greater than 1. With 1 OCPU, the concurrency limit for each service is 300 and the DOP is 1.OCPU is a legacy billing metric and has been retired on Autonomous Database. ECPUs are the replacement billing metric for all new and existing Autonomous Database deployments. See Oracle Support Document 2998742.1 for more information.
| Database Service Name | Concurrent Statements with OCPU Auto Scaling Disabled | Concurrent Statements with OCPU Auto Scaling Enabled |
|---|---|---|
|
|
300 × number of OCPUs | 300 × number of OCPUs |
|
|
300 × number of OCPUs | 300 × number of OCPUs |
|
|
3 | 9 |
|
|
1.26 × number of OCPUs | 3.78 × number of OCPUs |
|
|
300 × number of OCPUs | 300 × number of OCPUs |
See Database Service Names for Autonomous Database and Change MEDIUM Service Concurrency Limit (ECPU Compute Model) more information.