Overview

Parameter Template Type

When creating a DB instance, you can associate a default parameter template or a customized parameter template with the DB instance. After a DB instance is created, you can also change the associated parameter template.

• Default parameter template

  The DB engine parameter values and system service parameter values in the default parameter group are designed for optimizing the database performance.

• Custom parameter template

  If you need a DB instance with customized parameter settings, you can create a parameter template and change the parameter values as required.

  If you change the parameter values of the parameter template associated with several DB instances, the changes will apply to all these DB instances.

Application Scenarios

• If you want to use a customized parameter template, you only need to create a parameter template in advance and select the parameter template when creating a DB instance. For details about how to create a parameter template, see Creating a Parameter Template.
• When you have already created a parameter template and want to include most of the custom parameters and values from that template in a new parameter template, you can replicate that parameter template following the instructions provided in section Replicating a Parameter Template.

Precautions

• Default parameter templates are unchangeable. You can only view them by clicking their names. If inappropriate settings of customized parameter templates lead to a database startup failure, you can reset the customized parameter template by referring to the settings of the default parameter template.
• After modifying a parameter, you need to view the associated instance status in the instance list. If Pending restart is displayed, you need to restart the instance for the modification to take effect.
• Improperly setting parameters in a parameter template may have unintended adverse effects, including degraded performance and system instability. Exercise caution when modifying database parameters and you need to back up data before modifying parameters in a parameter template. Before applying parameter changes to a production DB instance, you should try out these changes on a test DB instance.