# Parameter groups for Amazon Aurora
*Database parameters* specify how the database is configured. For example, database parameters can specify the amount of resources, such as memory, to allocate to a database.
You manage your database configuration by associating your DB instances and Aurora DB clusters with parameter groups. Aurora defines parameter groups with default settings. You can also define your own parameter groups with customized settings.
**Topics**
+ [
# Overview of parameter groups
](parameter-groups-overview.md)
+ [
# DB cluster parameter groups for Amazon Aurora DB clusters
](USER_WorkingWithDBClusterParamGroups.md)
+ [
# DB parameter groups for Amazon Aurora DB instances
](USER_WorkingWithDBInstanceParamGroups.md)
+ [
# Comparing DB parameter groups
](USER_WorkingWithParamGroups.Comparing.md)
+ [
# Specifying DB parameters
](USER_ParamValuesRef.md)
# Overview of parameter groups
A *DB cluster parameter group* acts as a container for engine configuration values that apply to every DB instance in an Aurora DB cluster. For example, the Aurora shared storage model requires that every DB instance in an Aurora cluster use the same setting for parameters such as `innodb_file_per_table`. Thus, parameters that affect the physical storage layout are part of the cluster parameter group. The DB cluster parameter group also includes default values for all instance-level parameters.
A *DB parameter group* acts as a container for engine configuration values that are applied to one or more DB instances. DB parameter groups apply to DB instances in both Amazon RDS and Aurora. These configuration settings apply to properties that can vary among the DB instances within an Aurora cluster, such as the sizes for memory buffers.
**Topics**
+ [
## Default and custom parameter groups
](#parameter-groups-overview.custom)
+ [
## Static and dynamic DB cluster parameters
](#parameter-groups-overview.db-cluster)
+ [
## Static and dynamic DB instance parameters
](#parameter-groups-overview.db-instance)
+ [
## Character set parameters
](#parameter-groups-overview.char-sets)
+ [
## Supported parameters and parameter values
](#parameter-groups-overview.supported)
## Default and custom parameter groups
If you create a DB instance without specifying a DB parameter group, the DB instance uses a default DB parameter group. Likewise, if you create an Aurora DB cluster without specifying a DB cluster parameter group, the DB cluster uses a default DB cluster parameter group. Each default parameter group contains database engine defaults and Amazon RDS system defaults based on the engine, compute class, and allocated storage of the instance.
You can't modify the parameter settings of a default parameter group. Instead, you can do the following:
1. Create a new parameter group.
1. Change the settings of your desired parameters. Not all DB engine parameters in a parameter group are eligible to be modified.
1. Modify your DB instance or DB cluster to associate the new parameter group.
For information about modifying a DB cluster or DB instance, see [Modifying an Amazon Aurora DB cluster](Aurora.Modifying.md).
**Note**
If you have modified your DB instance to use a custom parameter group, and you start the DB instance, RDS automatically reboots the DB instance as part of the startup process. For RDS for SQL Server Multi-AZ instances with AlwaysOn or Mirroring option enabled, a failover is expected when instance is rebooted after the startup process.
RDS applies the modified static and dynamic parameters in a newly associated parameter group only after the DB instance is rebooted. However, if you modify dynamic parameters in the DB parameter group after you associate it with the DB instance, these changes are applied immediately without a reboot. For more information about changing the DB parameter group, see [Modifying an Amazon Aurora DB cluster](Aurora.Modifying.md).
If you update parameters within a DB parameter group, the changes apply to all DB instances that are associated with that parameter group. Likewise, if you update parameters within an Aurora DB cluster parameter group, the changes apply to all Aurora DB clusters that are associated with that DB cluster parameter group.
If you don't want to create a parameter group from scratch, you can copy an existing parameter group with the AWS CLI [copy-db-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-parameter-group.html) command or [copy-db-cluster-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-cluster-parameter-group.html) command. You might find that copying a parameter group is useful in some cases. For example, you might want to include most of an existing parameter group's custom parameters and values in a new parameter group.
## Static and dynamic DB cluster parameters
DB cluster parameters are either static or dynamic. They differ in the following ways:
+ When you change a static parameter and save the DB cluster parameter group, the parameter change takes effect after you manually reboot the DB instances in each associated DB cluster. When you use the AWS Management Console to change static DB cluster parameter values, it always uses `pending-reboot` for the `ApplyMethod`.
+ When you change a dynamic parameter, by default the parameter change takes effect immediately, without requiring a reboot. When you use the console, it always uses `immediate` for the `ApplyMethod`. To defer the parameter change until after you reboot the DB instances in an associated DB cluster, use the AWS CLI or RDS API. Set the `ApplyMethod` to `pending-reboot` for the parameter change.
For more information about using the AWS CLI to change a parameter value, see [modify-db-cluster-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-cluster-parameter-group.html). For more information about using the RDS API to change a parameter value, see [ModifyDBClusterParameterGroup](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBClusterParameterGroup.html).
If you change the DB cluster parameter group associated with a DB cluster, reboot the DB instances in the DB cluster. The reboot applies the changes to all DB instances in the DB cluster. To determine whether the DB instances of a DB cluster must be rebooted to apply changes, run the following AWS CLI command.
`aws rds describe-db-clusters --db-cluster-identifier db_cluster_identifier`
Check the `DBClusterParameterGroupStatus` value for the primary DB instance in the output. If the value is `pending-reboot`, then reboot the DB instances of the DB cluster.
## Static and dynamic DB instance parameters
DB instance parameters are either static or dynamic. They differ as follows:
+ When you change a static parameter and save the DB parameter group, the parameter change takes effect after you manually reboot the associated DB instances. For static parameters, the console always uses `pending-reboot` for the `ApplyMethod`.
+ When you change a dynamic parameter, by default the parameter change takes effect immediately, without requiring a reboot. When you use the AWS Management Console to change DB instance parameter values, it always uses `immediate` for the `ApplyMethod` for dynamic parameters. To defer the parameter change until after you reboot an associated DB instance, use the AWS CLI or RDS API. Set the `ApplyMethod` to `pending-reboot` for the parameter change.
For more information about using the AWS CLI to change a parameter value, see [modify-db-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-parameter-group.html). For more information about using the RDS API to change a parameter value, see [ModifyDBParameterGroup](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBParameterGroup.html).
If a DB instance isn't using the latest changes to its associated DB parameter group, the console shows a status of **pending-reboot** for the DB parameter group. This status doesn't result in an automatic reboot during the next maintenance window. To apply the latest parameter changes to that DB instance, manually reboot the DB instance.
## Character set parameters
Before you create a DB cluster, set any parameters that relate to the character set or collation of your database in your parameter group. Also do so before you create a database in it. In this way, you ensure that the default database and new databases use the character set and collation values that you specify. If you change character set or collation parameters, the parameter changes aren't applied to existing databases.
For some DB engines, you can change character set or collation values for an existing database using the `ALTER DATABASE` command, for example:
```
ALTER DATABASE database_name CHARACTER SET character_set_name COLLATE collation;
```
For more information about changing the character set or collation values for a database, check the documentation for your DB engine.
## Supported parameters and parameter values
To determine the supported parameters for your DB engine, view the parameters in the DB parameter group and DB cluster parameter group used by the DB instance or DB cluster. For more information, see [Viewing parameter values for a DB parameter group in Amazon Aurora](USER_WorkingWithParamGroups.Viewing.md) and [Viewing parameter values for a DB cluster parameter groupin Amazon Aurora](USER_WorkingWithParamGroups.ViewingCluster.md).
In many cases, you can specify integer and Boolean parameter values using expressions, formulas, and functions. Functions can include a mathematical log expression. However, not all parameters support expressions, formulas, and functions for parameter values. For more information, see [Specifying DB parameters](USER_ParamValuesRef.md).
For an Aurora global database, you can specify different configuration settings for the individual Aurora clusters. Make sure that the settings are similar enough to produce consistent behavior if you promote a secondary cluster to be the primary cluster. For example, use the same settings for time zones and character sets across all the clusters of an Aurora global database.
Improperly setting parameters in a parameter group can have unintended adverse effects, including degraded performance and system instability. Always be cautious when modifying database parameters, and back up your data before modifying a parameter group. Try parameter group setting changes on a test DB instance or DB cluster before applying those parameter group changes to a production DB instance or DB cluster.
# DB cluster parameter groups for Amazon Aurora DB clusters
Amazon Aurora DB clusters use DB cluster parameter groups. The following sections describe configuring and managing DB cluster parameter groups.
**Topics**
+ [
## Amazon Aurora DB cluster and DB instance parameters
](#Aurora.Managing.ParameterGroups)
+ [
# Creating a DB cluster parameter groupin Amazon Aurora
](USER_WorkingWithParamGroups.CreatingCluster.md)
+ [
# Associating a DB cluster parameter group with a DB cluster in Amazon Aurora
](USER_WorkingWithParamGroups.AssociatingCluster.md)
+ [
# Modifying parameters in a DB cluster parameter groupin Amazon Aurora
](USER_WorkingWithParamGroups.ModifyingCluster.md)
+ [
# Resetting parameters in a DB cluster parameter groupin Amazon Aurora
](USER_WorkingWithParamGroups.ResettingCluster.md)
+ [
# Copying a DB cluster parameter groupin Amazon Aurora
](USER_WorkingWithParamGroups.CopyingCluster.md)
+ [
# Listing DB cluster parameter groupsin Amazon Aurora
](USER_WorkingWithParamGroups.ListingCluster.md)
+ [
# Viewing parameter values for a DB cluster parameter groupin Amazon Aurora
](USER_WorkingWithParamGroups.ViewingCluster.md)
+ [
# Deleting a DB cluster parameter groupin Amazon Aurora
](USER_WorkingWithParamGroups.DeletingCluster.md)
## Amazon Aurora DB cluster and DB instance parameters
Aurora uses a two-level system of configuration settings:
+ Parameters in a *DB cluster parameter group* apply to every DB instance in a DB cluster. Your data is stored in the Aurora shared storage subsystem. Because of this, all parameters related to physical layout of table data must be the same for all DB instances in an Aurora cluster. Likewise, because Aurora DB instances are connected by replication, all the parameters for replication settings must be identical throughout an Aurora cluster.
+ Parameters in a *DB parameter group* apply to a single DB instance in an Aurora DB cluster. These parameters are related to aspects such as memory usage that you can vary across DB instances in the same Aurora cluster. For example, a cluster often contains DB instances with different AWS instance classes.
Every Aurora cluster is associated with a DB cluster parameter group. This parameter group assigns default values for every configuration value for the corresponding DB engine. The cluster parameter group includes defaults for both the cluster-level and instance-level parameters. Each DB instance within a provisioned or Aurora Serverless v2 cluster inherits the settings from that DB cluster parameter group.
Each DB instance is also associated with a DB parameter group. The values in the DB parameter group can override default values from the cluster parameter group. For example, if one instance in a cluster experienced issues, you might assign a custom DB parameter group to that instance. The custom parameter group might have specific settings for parameters related to debugging or performance tuning.
Aurora assigns default parameter groups when you create a cluster or a new DB instance, based on the specified database engine and version. You can specify custom parameter groups instead. You create those parameter groups yourself, and you can edit the parameter values. You can specify these custom parameter groups at creation time. You can also modify a DB cluster or instance later to use a custom parameter group.
For provisioned and Aurora Serverless v2 instances, any configuration values that you modify in the DB cluster parameter group override default values in the DB parameter group. If you edit the corresponding values in the DB parameter group, those values override the settings from the DB cluster parameter group.
Any DB parameter settings that you modify take precedence over the DB cluster parameter group values, even if you change the configuration parameters back to their default values. You can see which parameters are overridden by using the [describe-db-parameters](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameters.html) AWS CLI command or the [DescribeDBParameters](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameters.html) RDS API operation. The `Source` field contains the value `user` if you modified that parameter. To reset one or more parameters so that the value from the DB cluster parameter group takes precedence, use the [reset-db-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/reset-db-parameter-group.html) AWS CLI command or the [ResetDBParameterGroup](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ResetDBParameterGroup.html) RDS API operation.
The DB cluster and DB instance parameters available to you in Aurora vary depending on database engine compatibility.
| Database engine | Parameters |
| --- | --- |
| Aurora MySQL | See [Aurora MySQL configuration parameters](AuroraMySQL.Reference.ParameterGroups.md). For Aurora Serverless clusters, see additional details in [Working with parameter groups for Aurora Serverless v2](aurora-serverless-v2.setting-capacity.md#aurora-serverless-v2.parameter-groups). |
| Aurora PostgreSQL | See [Amazon Aurora PostgreSQL parameters](AuroraPostgreSQL.Reference.ParameterGroups.md). For Aurora Serverless clusters, see additional details in [Working with parameter groups for Aurora Serverless v2](aurora-serverless-v2.setting-capacity.md#aurora-serverless-v2.parameter-groups). |
**Note**
Aurora Serverless v2 uses both DB cluster parameter groups and DB parameter groups. With Aurora Serverless v2, you can modify almost all of the configuration parameters. Aurora Serverless v2 overrides the settings of some capacity-related configuration parameters so that your workload isn't interrupted when Aurora Serverless v2 instances scale down.
To learn more about Aurora Serverless configuration settings and which settings you can modify, see [Working with parameter groups for Aurora Serverless v2](aurora-serverless-v2.setting-capacity.md#aurora-serverless-v2.parameter-groups).
# Creating a DB cluster parameter groupin Amazon Aurora
You can create a new DB cluster parameter group using the AWS Management Console, the AWS CLI, or the RDS API.
After you create a DB cluster parameter group, wait at least 5 minutes before creating a DB cluster that uses that DB cluster parameter group. Doing this allows Amazon RDS to fully create the parameter group before it is used by the new DB cluster. You can use the **Parameter groups** page in the [Amazon RDS console](https://console.aws.amazon.com/rds/) or the [describe-db-cluster-parameters](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-cluster-parameters.html) command to verify that your DB cluster parameter group is created.
The following limitations apply to the DB cluster parameter group name:
+ The name must be 1 to 255 letters, numbers, or hyphens.
Default parameter group names can include a period, such as `default.aurora-mysql5.7`. However, custom parameter group names can't include a period.
+ The first character must be a letter.
+ The name can't end with a hyphen or contain two consecutive hyphens.
## Console
**To create a DB cluster parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. Choose **Create parameter group**.
1. For **Parameter group name**, enter the name of the new DB cluster parameter group.
1. For **Description**, enter a description for the new DB cluster parameter group.
1. For **Engine type**, choose your database engine.
1. For **Parameter group family**, choose a DB parameter group family.
1. Choose **Create**.
## AWS CLI
To create a DB cluster parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-cluster-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-cluster-parameter-group.html) command.
The following example creates a DB cluster parameter group named *mydbclusterparametergroup* for Aurora MySQL version 5.7 with a description of "*My new cluster parameter group*."
Include the following required parameters:
+ `--db-cluster-parameter-group-name`
+ `--db-parameter-group-family`
+ `--description`
To list all of the available parameter group families, use the following command:
```
aws rds describe-db-engine-versions --query "DBEngineVersions[].DBParameterGroupFamily"
```
**Note**
The output contains duplicates.
**Example**
For Linux, macOS, or Unix:
```
aws rds create-db-cluster-parameter-group \
--db-cluster-parameter-group-name mydbclusterparametergroup \
--db-parameter-group-family aurora-mysql5.7 \
--description "My new cluster parameter group"
```
For Windows:
```
aws rds create-db-cluster-parameter-group ^
--db-cluster-parameter-group-name mydbclusterparametergroup ^
--db-parameter-group-family aurora-mysql5.7 ^
--description "My new cluster parameter group"
```
This command produces output similar to the following:
```
{
"DBClusterParameterGroup": {
"DBClusterParameterGroupName": "mydbclusterparametergroup",
"DBParameterGroupFamily": "aurora-mysql5.7",
"Description": "My new cluster parameter group",
"DBClusterParameterGroupArn": "arn:aws:rds:us-east-1:123456789012:cluster-pg:mydbclusterparametergroup"
}
}
```
## RDS API
To create a DB cluster parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBClusterParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBClusterParameterGroup.html) action.
Include the following required parameters:
+ `DBClusterParameterGroupName`
+ `DBParameterGroupFamily`
+ `Description`
# Associating a DB cluster parameter group with a DB cluster in Amazon Aurora
You can create your own DB cluster parameter groups with customized settings. You can associate a DB cluster parameter group with a DB cluster using the AWS Management Console, the AWS CLI, or the RDS API. You can do so when you create or modify a DB cluster.
For information about creating a DB cluster parameter group, see [Creating a DB cluster parameter groupin Amazon Aurora](USER_WorkingWithParamGroups.CreatingCluster.md). For information about creating a DB cluster, see [Creating an Amazon Aurora DB cluster](Aurora.CreateInstance.md). For information about modifying a DB cluster, see [Modifying an Amazon Aurora DB cluster](Aurora.Modifying.md).
**Note**
For Aurora PostgreSQL 15.2, 14.7, 13.10, 12.14, and all 11 versions, when you change the DB cluster parameter group associated with a DB cluster, reboot each replica instance to apply the changes.
To determine whether the primary DB instance of a DB cluster must be rebooted to apply changes, run the following AWS CLI command:
`aws rds describe-db-clusters --db-cluster-identifier db_cluster_identifier`
Check the `DBClusterParameterGroupStatus` value for the primary DB instance in the output. If the value is `pending-reboot`, then reboot the primary DB instance of the DB cluster.
## Console
**To associate a DB cluster parameter group with a DB cluster**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Databases**, and then select the DB cluster that you want to modify.
1. Choose **Modify**. The **Modify DB cluster** page appears.
1. Change the **DB cluster parameter group** setting.
1. Choose **Continue** and check the summary of modifications.
The change is applied immediately regardless of the **Scheduling of modifications** setting.
1. On the confirmation page, review your changes. If they are correct, choose **Modify cluster** to save your changes.
Alternatively, choose **Back** to edit your changes, or choose **Cancel** to cancel your changes.
## AWS CLI
To associate a DB cluster parameter group with a DB cluster, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-cluster.html](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-cluster.html) command with the following options:
+ `--db-cluster-name`
+ `--db-cluster-parameter-group-name`
The following example associates the `mydbclpg` DB parameter group with the `mydbcluster` DB cluster.
**Example**
For Linux, macOS, or Unix:
```
aws rds modify-db-cluster \
--db-cluster-identifier mydbcluster \
--db-cluster-parameter-group-name mydbclpg
```
For Windows:
```
aws rds modify-db-cluster ^
--db-cluster-identifier mydbcluster ^
--db-cluster-parameter-group-name mydbclpg
```
## RDS API
To associate a DB cluster parameter group with a DB cluster, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBCluster.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBCluster.html) operation with the following parameters:
+ `DBClusterIdentifier`
+ `DBClusterParameterGroupName`
# Modifying parameters in a DB cluster parameter groupin Amazon Aurora
You can modify parameter values in a customer-created DB cluster parameter group. You can't change the parameter values in a default DB cluster parameter group. Changes to parameters in a customer-created DB cluster parameter group are applied to all DB clusters that are associated with the DB cluster parameter group.
## Console
**To modify a DB cluster parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the parameter group that you want to modify.
1. For **Parameter group actions**, choose **Edit**.
1. Change the values of the parameters you want to modify. You can scroll through the parameters using the arrow keys at the top right of the dialog box.
You can't change values in a default parameter group.
1. Choose **Save changes**.
1. Reboot the primary (writer) DB instance in the cluster to apply the changes to it.
1. Then reboot the reader DB instances to apply the changes to them.
If you don't reboot the DB instances, then a failover operation could take longer than normal.
## AWS CLI
To modify a DB cluster parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-cluster-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-cluster-parameter-group.html) command with the following required parameters:
+ `--db-cluster-parameter-group-name`
+ `--parameters`
The following example modifies the `server_audit_logging` and `server_audit_logs_upload` values in the DB cluster parameter group named *mydbclusterparametergroup*.
**Example**
For Linux, macOS, or Unix:
```
aws rds modify-db-cluster-parameter-group \
--db-cluster-parameter-group-name mydbclusterparametergroup \
--parameters "ParameterName=server_audit_logging,ParameterValue=1,ApplyMethod=immediate" \
"ParameterName=server_audit_logs_upload,ParameterValue=1,ApplyMethod=immediate"
```
For Windows:
```
aws rds modify-db-cluster-parameter-group ^
--db-cluster-parameter-group-name mydbclusterparametergroup ^
--parameters "ParameterName=server_audit_logging,ParameterValue=1,ApplyMethod=immediate" ^
"ParameterName=server_audit_logs_upload,ParameterValue=1,ApplyMethod=immediate"
```
The command produces output like the following:
```
DBCLUSTERPARAMETERGROUP mydbclusterparametergroup
```
## RDS API
To modify a DB cluster parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBClusterParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBClusterParameterGroup.html) command with the following required parameters:
+ `DBClusterParameterGroupName`
+ `Parameters`
# Resetting parameters in a DB cluster parameter groupin Amazon Aurora
You can reset parameters to their default values in a customer-created DB cluster parameter group. Changes to parameters in a customer-created DB cluster parameter group are applied to all DB clusters that are associated with the DB cluster parameter group.
**Note**
In a default DB cluster parameter group, parameters are always set to their default values.
## Console
**To reset parameters in a DB cluster parameter group to their default values**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the parameter group.
1. For **Parameter group actions**, choose **Edit**.
1. Choose the parameters that you want to reset to their default values. You can scroll through the parameters using the arrow keys at the top right of the dialog box.
You can't reset values in a default parameter group.
1. Choose **Reset** and then confirm by choosing **Reset parameters**.
1. Reboot the primary DB instance in the DB cluster to apply the changes to all of the DB instances in the DB cluster.
## AWS CLI
To reset parameters in a DB cluster parameter group to their default values, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/reset-db-cluster-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/reset-db-cluster-parameter-group.html) command with the following required option: `--db-cluster-parameter-group-name`.
To reset all of the parameters in the DB cluster parameter group, specify the `--reset-all-parameters` option. To reset specific parameters, specify the `--parameters` option.
The following example resets all of the parameters in the DB parameter group named *mydbparametergroup* to their default values.
**Example**
For Linux, macOS, or Unix:
```
aws rds reset-db-cluster-parameter-group \
--db-cluster-parameter-group-name mydbparametergroup \
--reset-all-parameters
```
For Windows:
```
aws rds reset-db-cluster-parameter-group ^
--db-cluster-parameter-group-name mydbparametergroup ^
--reset-all-parameters
```
The following example resets the `server_audit_logging` and `server_audit_logs_upload` to their default values in the DB cluster parameter group named *mydbclusterparametergroup*.
**Example**
For Linux, macOS, or Unix:
```
aws rds reset-db-cluster-parameter-group \
--db-cluster-parameter-group-name mydbclusterparametergroup \
--parameters "ParameterName=server_audit_logging,ApplyMethod=immediate" \
"ParameterName=server_audit_logs_upload,ApplyMethod=immediate"
```
For Windows:
```
aws rds reset-db-cluster-parameter-group ^
--db-cluster-parameter-group-name mydbclusterparametergroup ^
--parameters "ParameterName=server_audit_logging,ParameterValue=1,ApplyMethod=immediate" ^
"ParameterName=server_audit_logs_upload,ParameterValue=1,ApplyMethod=immediate"
```
The command produces output like the following:
```
DBClusterParameterGroupName mydbclusterparametergroup
```
## RDS API
To reset parameters in a DB cluster parameter group to their default values, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ResetDBClusterParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ResetDBClusterParameterGroup.html) command with the following required parameter: `DBClusterParameterGroupName`.
To reset all of the parameters in the DB cluster parameter group, set the `ResetAllParameters` parameter to `true`. To reset specific parameters, specify the `Parameters` parameter.
# Copying a DB cluster parameter groupin Amazon Aurora
You can copy custom DB cluster parameter groups that you create. Copying a parameter group is a convenient solution when you have already created a DB cluster parameter group and you want to include most of the custom parameters and values from that group in a new DB cluster parameter group. You can copy a DB cluster parameter group by using the AWS CLI [copy-db-cluster-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-cluster-parameter-group.html) command or the RDS API [CopyDBClusterParameterGroup](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CopyDBParameterGroup.html) operation.
After you copy a DB cluster parameter group, wait at least 5 minutes before creating a DB cluster that uses that DB cluster parameter group. Doing this allows Amazon RDS to fully copy the parameter group before it is used by the new DB cluster. You can use the **Parameter groups** page in the [Amazon RDS console](https://console.aws.amazon.com/rds/) or the [describe-db-cluster-parameters](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-cluster-parameters.html) command to verify that your DB cluster parameter group is created.
**Note**
You can't copy a default parameter group. However, you can create a new parameter group that is based on a default parameter group.
You can't copy a DB cluster parameter group to a different AWS account or AWS Region.
## Console
**To copy a DB cluster parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the custom parameter group that you want to copy.
1. For **Parameter group actions**, choose **Copy**.
1. In **New DB parameter group identifier**, enter a name for the new parameter group.
1. In **Description**, enter a description for the new parameter group.
1. Choose **Copy**.
## AWS CLI
To copy a DB cluster parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-cluster-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-cluster-parameter-group.html) command with the following required parameters:
+ `--source-db-cluster-parameter-group-identifier`
+ `--target-db-cluster-parameter-group-identifier`
+ `--target-db-cluster-parameter-group-description`
The following example creates a new DB cluster parameter group named `mygroup2` that is a copy of the DB cluster parameter group `mygroup1`.
**Example**
For Linux, macOS, or Unix:
```
aws rds copy-db-cluster-parameter-group \
--source-db-cluster-parameter-group-identifier mygroup1 \
--target-db-cluster-parameter-group-identifier mygroup2 \
--target-db-cluster-parameter-group-description "DB parameter group 2"
```
For Windows:
```
aws rds copy-db-cluster-parameter-group ^
--source-db-cluster-parameter-group-identifier mygroup1 ^
--target-db-cluster-parameter-group-identifier mygroup2 ^
--target-db-cluster-parameter-group-description "DB parameter group 2"
```
## RDS API
To copy a DB cluster parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CopyDBClusterParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CopyDBClusterParameterGroup.html) operation with the following required parameters:
+ `SourceDBClusterParameterGroupIdentifier`
+ `TargetDBClusterParameterGroupIdentifier`
+ `TargetDBClusterParameterGroupDescription`
# Listing DB cluster parameter groupsin Amazon Aurora
You can list the DB cluster parameter groups you've created for your AWS account.
**Note**
Default parameter groups are automatically created from a default parameter template when you create a DB cluster for a particular DB engine and version. These default parameter groups contain preferred parameter settings and can't be modified. When you create a custom parameter group, you can modify parameter settings.
## Console
**To list all DB cluster parameter groups for an AWS account**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
The DB cluster parameter groups appear in the list with **DB cluster parameter group** for **Type**.
## AWS CLI
To list all DB cluster parameter groups for an AWS account, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-clusterparameter-groups.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-clusterparameter-groups.html) command.
**Example**
The following example lists all available DB cluster parameter groups for an AWS account.
```
aws rds describe-db-cluster-parameter-groups
```
The following example describes the *mydbclusterparametergroup* parameter group.
For Linux, macOS, or Unix:
```
aws rds describe-db-cluster-parameter-groups \
--db-cluster-parameter-group-name mydbclusterparametergroup
```
For Windows:
```
aws rds describe-db-cluster-parameter-groups ^
--db-cluster-parameter-group-name mydbclusterparametergroup
```
The command returns a response like the following:
```
{
"DBClusterParameterGroups": [
{
"DBClusterParameterGroupName": "mydbclusterparametergroup",
"DBParameterGroupFamily": "aurora-mysql5.7",
"Description": "My new cluster parameter group",
"DBClusterParameterGroupArn": "arn:aws:rds:us-east-1:123456789012:cluster-pg:mydbclusterparametergroup"
}
]
}
```
## RDS API
To list all DB cluster parameter groups for an AWS account, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBClusterParameterGroups.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBClusterParameterGroups.html) action.
# Viewing parameter values for a DB cluster parameter groupin Amazon Aurora
You can get a list of all parameters in a DB cluster parameter group and their values.
## Console
**To view the parameter values for a DB cluster parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
The DB cluster parameter groups appear in the list with **DB cluster parameter group** for **Type**.
1. Choose the name of the DB cluster parameter group to see its list of parameters.
## AWS CLI
To view the parameter values for a DB cluster parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-cluster-parameters.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-cluster-parameters.html) command with the following required parameter.
+ `--db-cluster-parameter-group-name`
**Example**
The following example lists the parameters and parameter values for a DB cluster parameter group named *mydbclusterparametergroup*, in JSON format.
The command returns a response like the following:
```
aws rds describe-db-cluster-parameters --db-cluster-parameter-group-name mydbclusterparametergroup
```
```
{
"Parameters": [
{
"ParameterName": "allow-suspicious-udfs",
"Description": "Controls whether user-defined functions that have only an xxx symbol for the main function can be loaded",
"Source": "engine-default",
"ApplyType": "static",
"DataType": "boolean",
"AllowedValues": "0,1",
"IsModifiable": false,
"ApplyMethod": "pending-reboot",
"SupportedEngineModes": [
"provisioned"
]
},
{
"ParameterName": "aurora_binlog_read_buffer_size",
"ParameterValue": "5242880",
"Description": "Read buffer size used by master dump thread when the switch aurora_binlog_use_large_read_buffer is ON.",
"Source": "engine-default",
"ApplyType": "dynamic",
"DataType": "integer",
"AllowedValues": "8192-536870912",
"IsModifiable": true,
"ApplyMethod": "pending-reboot",
"SupportedEngineModes": [
"provisioned"
]
},
...
```
## RDS API
To view the parameter values for a DB cluster parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameters.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameters.html) command with the following required parameter.
+ `DBClusterParameterGroupName`
In some cases, the allowed values for a parameter aren't shown. These are always parameters where the source is the database engine default.
To view the values of these parameters, you can run the following SQL statements:
+ MySQL:
```
-- Show the value of a particular parameter
mysql$ SHOW VARIABLES LIKE '%parameter_name%';
-- Show the values of all parameters
mysql$ SHOW VARIABLES;
```
+ PostgreSQL:
```
-- Show the value of a particular parameter
postgresql=> SHOW parameter_name;
-- Show the values of all parameters
postgresql=> SHOW ALL;
```
# Deleting a DB cluster parameter groupin Amazon Aurora
You can delete a DB cluster parameter group using the AWS Management Console, AWS CLI, or RDS API. A DB cluster parameter group parameter group is eligible for deletion only if it isn't associated with a DB cluster.
## Console
**To delete parameter groups**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
The parameter groups appear in a list.
1. Choose the name of the DB cluster parameter groups to be deleted.
1. Choose **Actions** and then **Delete**.
1. Review the parameter group names and then choose **Delete**.
## AWS CLI
To delete a DB cluster parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/delete-db-cluster-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/delete-db-cluster-parameter-group.html) command with the following required parameter.
+ `--db-parameter-group-name`
**Example**
The following example deletes a DB cluster parameter group named *mydbparametergroup.*
```
aws rds delete-db-cluster-parameter-group --db-parameter-group-name mydbparametergroup
```
## RDS API
To delete a DB cluster parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DeleteDBClusterParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DeleteDBClusterParameterGroup.html) command with the following required parameter.
+ `DBParameterGroupName`
# DB parameter groups for Amazon Aurora DB instances
DB instances use DB parameter groups. The following sections describe configuring and managing DB instance parameter groups.
**Topics**
+ [
# Creating a DB parameter group in Amazon Aurora
](USER_WorkingWithParamGroups.Creating.md)
+ [
# Associating a DB parameter group with a DB instance in Amazon Aurora
](USER_WorkingWithParamGroups.Associating.md)
+ [
# Modifying parameters in a DB parameter group in Amazon Aurora
](USER_WorkingWithParamGroups.Modifying.md)
+ [
# Resetting parameters in a DB parameter group to their default values in Amazon Aurora
](USER_WorkingWithParamGroups.Resetting.md)
+ [
# Copying a DB parameter group in Amazon Aurora
](USER_WorkingWithParamGroups.Copying.md)
+ [
# Listing DB parameter groups in Amazon Aurora
](USER_WorkingWithParamGroups.Listing.md)
+ [
# Viewing parameter values for a DB parameter group in Amazon Aurora
](USER_WorkingWithParamGroups.Viewing.md)
+ [
# Deleting a DB parameter group in Amazon Aurora
](USER_WorkingWithParamGroups.Deleting.md)
# Creating a DB parameter group in Amazon Aurora
You can create a new DB parameter group using the AWS Management Console, the AWS CLI, or the RDS API.
The following limitations apply to the DB parameter group name:
+ The name must be 1 to 255 letters, numbers, or hyphens.
Default parameter group names can include a period, such as `default.mysql8.0`. However, custom parameter group names can't include a period.
+ The first character must be a letter.
+ The name can't end with a hyphen or contain two consecutive hyphens.
## Console
**To create a DB parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. Choose **Create parameter group**.
1. For **Parameter group name**, enter the name of your new DB parameter group.
1. For **Description**, enter a description for your new DB parameter group.
1. For **Engine type**, choose your DB engine.
1. For **Parameter group family**, choose a DB parameter group family.
1. For **Type**, if applicable, choose **DB Parameter Group**.
1. Choose **Create**.
## AWS CLI
To create a DB parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-parameter-group.html) command. The following example creates a DB parameter group named *mydbparametergroup* for MySQL version 8.0 with a description of "*My new parameter group*."
Include the following required parameters:
+ `--db-parameter-group-name`
+ `--db-parameter-group-family`
+ `--description`
To list all of the available parameter group families, use the following command:
```
aws rds describe-db-engine-versions --query "DBEngineVersions[].DBParameterGroupFamily"
```
**Note**
The output contains duplicates.
**Example**
For Linux, macOS, or Unix:
```
aws rds create-db-parameter-group \
--db-parameter-group-name mydbparametergroup \
--db-parameter-group-family aurora-mysql5.7 \
--description "My new parameter group"
```
For Windows:
```
aws rds create-db-parameter-group ^
--db-parameter-group-name mydbparametergroup ^
--db-parameter-group-family aurora-mysql5.7 ^
--description "My new parameter group"
```
This command produces output similar to the following:
```
DBPARAMETERGROUP mydbparametergroup aurora-mysql5.7 My new parameter group
```
## RDS API
To create a DB parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBParameterGroup.html) operation.
Include the following required parameters:
+ `DBParameterGroupName`
+ `DBParameterGroupFamily`
+ `Description`
# Associating a DB parameter group with a DB instance in Amazon Aurora
You can create your own DB parameter groups with customized settings. You can associate a DB parameter group with a DB instance using the AWS Management Console, the AWS CLI, or the RDS API. You can do so when you create or modify a DB instance.
For information about creating a DB parameter group, see [Creating a DB parameter group in Amazon Aurora](USER_WorkingWithParamGroups.Creating.md). For information about modifying a DB instance, see [Modifying a DB instance in a DB cluster](Aurora.Modifying.md#Aurora.Modifying.Instance).
**Note**
When you associate a new DB parameter group with a DB instance, the modified static and dynamic parameters are applied only after the DB instance is rebooted. However, if you modify dynamic parameters in the DB parameter group after you associate it with the DB instance, these changes are applied immediately without a reboot.
## Console
**To associate a DB parameter group with a DB instance**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Databases**, and then choose the DB instance that you want to modify.
1. Choose **Modify**. The **Modify DB instance** page appears.
1. Change the **DB parameter group** setting.
1. Choose **Continue** and check the summary of modifications.
1. (Optional) Choose **Apply immediately** to apply the changes immediately. Choosing this option can cause an outage in some cases.
1. On the confirmation page, review your changes. If they are correct, choose **Modify DB instance** to save your changes.
Or choose **Back** to edit your changes or **Cancel** to cancel your changes.
## AWS CLI
To associate a DB parameter group with a DB instance, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-instance.html](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-instance.html) command with the following options:
+ `--db-instance-identifier`
+ `--db-parameter-group-name`
The following example associates the `mydbpg` DB parameter group with the `database-1` DB instance. The changes are applied immediately by using `--apply-immediately`. Use `--no-apply-immediately` to apply the changes during the next maintenance window.
**Example**
For Linux, macOS, or Unix:
```
aws rds modify-db-instance \
--db-instance-identifier database-1 \
--db-parameter-group-name mydbpg \
--apply-immediately
```
For Windows:
```
aws rds modify-db-instance ^
--db-instance-identifier database-1 ^
--db-parameter-group-name mydbpg ^
--apply-immediately
```
## RDS API
To associate a DB parameter group with a DB instance, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBInstance.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBInstance.html) operation with the following parameters:
+ `DBInstanceName`
+ `DBParameterGroupName`
# Modifying parameters in a DB parameter group in Amazon Aurora
You can modify parameter values in a customer-created DB parameter group; you can't change the parameter values in a default DB parameter group. Changes to parameters in a customer-created DB parameter group are applied to all DB instances that are associated with the DB parameter group.
There are two types of parameters: dynamic parameters and static parameters. Changes to dynamic parameters are applied to the DB instance immediately without a reboot. Changes to static parameters are applied only after the DB instance is rebooted.
The RDS console shows the status of the DB parameter group associated with a DB instance on the **Configuration** tab. For example, if the DB instance isn't using the latest changes to its associated DB parameter group, the RDS console shows the DB parameter group with a status of **pending-reboot**. To apply the latest parameter changes to that DB instance, manually reboot the DB instance.
![\[Parameter change pending reboot scenario\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/images/db-cluster-instance-param-group.png)
## Console
**To modify the parameters in a DB parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the name of the parameter group that you want to modify.
1. For **Parameter group actions**, choose **Edit**.
1. Change the values of the parameters that you want to modify. You can scroll through the parameters using the arrow keys at the top right of the dialog box.
You can't change values in a default parameter group.
1. Choose **Save changes**.
## AWS CLI
To modify a DB parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-parameter-group.html) command with the following required options:
+ `--db-parameter-group-name`
+ `--parameters`
The following example modifies the` max_connections` and `max_allowed_packet` values in the DB parameter group named *mydbparametergroup*.
**Example**
For Linux, macOS, or Unix:
```
aws rds modify-db-parameter-group \
--db-parameter-group-name mydbparametergroup \
--parameters "ParameterName=max_connections,ParameterValue=250,ApplyMethod=immediate" \
"ParameterName=max_allowed_packet,ParameterValue=1024,ApplyMethod=immediate"
```
For Windows:
```
aws rds modify-db-parameter-group ^
--db-parameter-group-name mydbparametergroup ^
--parameters "ParameterName=max_connections,ParameterValue=250,ApplyMethod=immediate" ^
"ParameterName=max_allowed_packet,ParameterValue=1024,ApplyMethod=immediate"
```
The command produces output like the following:
```
DBPARAMETERGROUP mydbparametergroup
```
## RDS API
To modify a DB parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBParameterGroup.html) operation with the following required parameters:
+ `DBParameterGroupName`
+ `Parameters`
# Resetting parameters in a DB parameter group to their default values in Amazon Aurora
You can reset parameter values in a customer-created DB parameter group to their default values. Changes to parameters in a customer-created DB parameter group are applied to all DB instances that are associated with the DB parameter group.
When you use the console, you can reset specific parameters to their default values. However, you can't easily reset all of the parameters in the DB parameter group at once. When you use the AWS CLI or RDS API, you can reset specific parameters to their default values. You can also reset all of the parameters in the DB parameter group at once.
Changes to some parameters are applied to the DB instance immediately without a reboot. Changes to other parameters are applied only after the DB instance is rebooted. The RDS console shows the status of the DB parameter group associated with a DB instance on the **Configuration** tab. For example, suppose that the DB instance isn't using the latest changes to its associated DB parameter group. If so, the RDS console shows the DB parameter group with a status of **pending-reboot**. To apply the latest parameter changes to that DB instance, manually reboot the DB instance.
![\[Parameter change pending reboot scenario\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/images/db-cluster-instance-param-group.png)
**Note**
In a default DB parameter group, parameters are always set to their default values.
## Console
**To reset parameters in a DB parameter group to their default values**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the parameter group.
1. For **Parameter group actions**, choose **Edit**.
1. Choose the parameters that you want to reset to their default values. You can scroll through the parameters using the arrow keys at the top right of the dialog box.
You can't reset values in a default parameter group.
1. Choose **Reset** and then confirm by choosing **Reset parameters**.
## AWS CLI
To reset some or all of the parameters in a DB parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/reset-db-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/reset-db-parameter-group.html) command with the following required option: `--db-parameter-group-name`.
To reset all of the parameters in the DB parameter group, specify the `--reset-all-parameters` option. To reset specific parameters, specify the `--parameters` option.
The following example resets all of the parameters in the DB parameter group named *mydbparametergroup* to their default values.
**Example**
For Linux, macOS, or Unix:
```
aws rds reset-db-parameter-group \
--db-parameter-group-name mydbparametergroup \
--reset-all-parameters
```
For Windows:
```
aws rds reset-db-parameter-group ^
--db-parameter-group-name mydbparametergroup ^
--reset-all-parameters
```
The following example resets the `max_connections` and `max_allowed_packet` options to their default values in the DB parameter group named *mydbparametergroup*.
**Example**
For Linux, macOS, or Unix:
```
aws rds reset-db-parameter-group \
--db-parameter-group-name mydbparametergroup \
--parameters "ParameterName=max_connections,ApplyMethod=immediate" \
"ParameterName=max_allowed_packet,ApplyMethod=immediate"
```
For Windows:
```
aws rds reset-db-parameter-group ^
--db-parameter-group-name mydbparametergroup ^
--parameters "ParameterName=max_connections,ApplyMethod=immediate" ^
"ParameterName=max_allowed_packet,ApplyMethod=immediate"
```
The command produces output like the following:
```
DBParameterGroupName mydbparametergroup
```
## RDS API
To reset parameters in a DB parameter group to their default values, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ResetDBParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ResetDBParameterGroup.html) command with the following required parameter: `DBParameterGroupName`.
To reset all of the parameters in the DB parameter group, set the `ResetAllParameters` parameter to `true`. To reset specific parameters, specify the `Parameters` parameter.
# Copying a DB parameter group in Amazon Aurora
You can copy custom DB parameter groups that you create. Copying a parameter group can be convenient solution. An example is when you have created a DB parameter group and want to include most of its custom parameters and values in a new DB parameter group. You can copy a DB parameter group by using the AWS Management Console. You can also use the AWS CLI [copy-db-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-parameter-group.html) command or the RDS API [CopyDBParameterGroup](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CopyDBParameterGroup.html) operation.
After you copy a DB parameter group, wait at least 5 minutes before creating your first DB instance that uses that DB parameter group as the default parameter group. Doing this allows Amazon RDS to fully complete the copy action before the parameter group is used. This is especially important for parameters that are critical when creating the default database for a DB instance. An example is the character set for the default database defined by the `character_set_database` parameter. Use the **Parameter Groups** option of the [Amazon RDS console](https://console.aws.amazon.com/rds/) or the [describe-db-parameters](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameters.html) command to verify that your DB parameter group is created.
**Note**
You can't copy a default parameter group. However, you can create a new parameter group that is based on a default parameter group.
You can't copy a DB parameter group to a different AWS account or AWS Region.
## Console
**To copy a DB parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the custom parameter group that you want to copy.
1. For **Parameter group actions**, choose **Copy**.
1. In **New DB parameter group identifier**, enter a name for the new parameter group.
1. In **Description**, enter a description for the new parameter group.
1. Choose **Copy**.
## AWS CLI
To copy a DB parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/copy-db-parameter-group.html) command with the following required options:
+ `--source-db-parameter-group-identifier`
+ `--target-db-parameter-group-identifier`
+ `--target-db-parameter-group-description`
The following example creates a new DB parameter group named `mygroup2` that is a copy of the DB parameter group `mygroup1`.
**Example**
For Linux, macOS, or Unix:
```
aws rds copy-db-parameter-group \
--source-db-parameter-group-identifier mygroup1 \
--target-db-parameter-group-identifier mygroup2 \
--target-db-parameter-group-description "DB parameter group 2"
```
For Windows:
```
aws rds copy-db-parameter-group ^
--source-db-parameter-group-identifier mygroup1 ^
--target-db-parameter-group-identifier mygroup2 ^
--target-db-parameter-group-description "DB parameter group 2"
```
## RDS API
To copy a DB parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CopyDBParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CopyDBParameterGroup.html) operation with the following required parameters:
+ `SourceDBParameterGroupIdentifier`
+ `TargetDBParameterGroupIdentifier`
+ `TargetDBParameterGroupDescription`
# Listing DB parameter groups in Amazon Aurora
You can list the DB parameter groups you've created for your AWS account.
**Note**
Default parameter groups are automatically created from a default parameter template when you create a DB instance for a particular DB engine and version. These default parameter groups contain preferred parameter settings and can't be modified. When you create a custom parameter group, you can modify parameter settings.
## Console
**To list all DB parameter groups for an AWS account**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
The DB parameter groups appear in a list.
## AWS CLI
To list all DB parameter groups for an AWS account, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameter-groups.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameter-groups.html) command.
**Example**
The following example lists all available DB parameter groups for an AWS account.
```
aws rds describe-db-parameter-groups
```
The command returns a response like the following:
```
DBPARAMETERGROUP default.mysql8.0 mysql8.0 Default parameter group for MySQL8.0
DBPARAMETERGROUP mydbparametergroup mysql8.0 My new parameter group
```
The following example describes the *mydbparamgroup1* parameter group.
For Linux, macOS, or Unix:
```
aws rds describe-db-parameter-groups \
--db-parameter-group-name mydbparamgroup1
```
For Windows:
```
aws rds describe-db-parameter-groups ^
--db-parameter-group-name mydbparamgroup1
```
The command returns a response like the following:
```
DBPARAMETERGROUP mydbparametergroup1 mysql8.0 My new parameter group
```
## RDS API
To list all DB parameter groups for an AWS account, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameterGroups.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameterGroups.html) operation.
# Viewing parameter values for a DB parameter group in Amazon Aurora
You can get a list of all parameters in a DB parameter group and their values.
## Console
**To view the parameter values for a DB parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
The DB parameter groups appear in a list.
1. Choose the name of the parameter group to see its list of parameters.
## AWS CLI
To view the parameter values for a DB parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameters.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameters.html) command with the following required parameter.
+ `--db-parameter-group-name`
**Example**
The following example lists the parameters and parameter values for a DB parameter group named *mydbparametergroup.*
```
aws rds describe-db-parameters --db-parameter-group-name mydbparametergroup
```
The command returns a response like the following:
```
DBPARAMETER Parameter Name Parameter Value Source Data Type Apply Type Is Modifiable
DBPARAMETER allow-suspicious-udfs engine-default boolean static false
DBPARAMETER auto_increment_increment engine-default integer dynamic true
DBPARAMETER auto_increment_offset engine-default integer dynamic true
DBPARAMETER binlog_cache_size 32768 system integer dynamic true
DBPARAMETER socket /tmp/mysql.sock system string static false
```
## RDS API
To view the parameter values for a DB parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameters.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DescribeDBParameters.html) command with the following required parameter.
+ `DBParameterGroupName`
# Deleting a DB parameter group in Amazon Aurora
You can delete a DB parameter group using the AWS Management Console, AWS CLI, or RDS API. A parameter group is eligible for deletion only if it isn't associated with a DB instance.
## Console
**To delete a DB parameter group**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
The DB parameter groups appear in a list.
1. Choose the name of the parameter groups to be deleted.
1. Choose **Actions** and then **Delete**.
1. Review the parameter group names and then choose **Delete**.
## AWS CLI
To delete a DB parameter group, use the AWS CLI [https://docs.aws.amazon.com/cli/latest/reference/rds/delete-db-parameter-group.html](https://docs.aws.amazon.com/cli/latest/reference/rds/delete-db-parameter-group.html) command with the following required parameter.
+ `--db-parameter-group-name`
**Example**
The following example deletes a DB parameter group named *mydbparametergroup.*
```
aws rds delete-db-parameter-group --db-parameter-group-name mydbparametergroup
```
## RDS API
To delete a DB parameter group, use the RDS API [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DeleteDBParameterGroup.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DeleteDBParameterGroup.html) command with the following required parameter.
+ `DBParameterGroupName`
# Comparing DB parameter groups
You can use the AWS Management Console to view the differences between two DB parameter groups.
The specified parameter groups must both be DB parameter groups, or they both must be DB cluster parameter groups. This is true even when the DB engine and version are the same. For example, you can't compare an `aurora-mysql8.0` (Aurora MySQL version 3) DB parameter group and an `aurora-mysql8.0` DB cluster parameter group.
You can compare Aurora MySQL and RDS for MySQL DB parameter groups, even for different versions, but you can't compare Aurora PostgreSQL and RDS for PostgreSQL DB parameter groups.
**To compare two DB parameter groups**
1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/).
1. In the navigation pane, choose **Parameter groups**.
1. In the list, choose the two parameter groups that you want to compare.
**Note**
To compare a default parameter group to a custom parameter group, first choose the default parameter group on the **Default** tab, then choose the custom parameter group on the **Custom** tab.
1. From **Actions**, choose **Compare**.
# Specifying DB parameters
DB parameter types include the following:
+ Integer
+ Boolean
+ String
+ Long
+ Double
+ Timestamp
+ Object of other defined data types
+ Array of values of type integer, Boolean, string, long, double, timestamp, or object
You can also specify integer and Boolean parameters using expressions, formulas, and functions.
**Contents**
+ [
## DB parameter formulas
](#USER_ParamFormulas)
+ [
### DB parameter formula variables
](#USER_FormulaVariables)
+ [
### DB parameter formula operators
](#USER_FormulaOperators)
+ [
## DB parameter functions
](#USER_ParamFunctions)
+ [
## DB parameter log expressions
](#USER_ParamLogExpressions)
+ [
## DB parameter value examples
](#USER_ParamValueExamples)
## DB parameter formulas
A DB parameter formula is an expression that resolves to an integer value or a Boolean value. You enclose the expression in braces: \$1\$1. You can use a formula for either a DB parameter value or as an argument to a DB parameter function.
**Syntax**
```
{FormulaVariable}
{FormulaVariable*Integer}
{FormulaVariable*Integer/Integer}
{FormulaVariable/Integer}
```
### DB parameter formula variables
Each formula variable returns an integer or a Boolean value. The names of the variables are case-sensitive.
*AllocatedStorage*
Returns an integer representing the size, in bytes, of the data volume.
*DBInstanceClassMemory*
Returns an integer for the number of bytes of memory available to the database process. This number is internally calculated by starting with the total amount of memory for the DB instance class. From this, the calculation subtracts memory reserved for the operating system and the RDS processes that manage the instance. Therefore, the number is always somewhat lower than the memory figures shown in the instance class tables in [Amazon AuroraDB instance classes](Concepts.DBInstanceClass.md). The exact value depends on a combination of factors. These include instance class, DB engine, and whether it applies to an RDS instance or an instance that's part of an Aurora cluster.
*DBInstanceVCPU*
Returns an integer representing the number of virtual central processing units (vCPUs) used by Amazon RDS to manage the instance.
*EndPointPort*
Returns an integer representing the port used when connecting to the DB instance.
*TrueIfReplica*
Returns `1` if the DB instance is a read replica and `0` if it is not. This is the default value for the `read_only` parameter in Aurora MySQL.
### DB parameter formula operators
DB parameter formulas support two operators: division and multiplication.
*Division operator: /*
Divides the dividend by the divisor, returning an integer quotient. Decimals in the quotient are truncated, not rounded.
Syntax
```
dividend / divisor
```
The dividend and divisor arguments must be integer expressions.
*Multiplication operator: \$1*
Multiplies the expressions, returning the product of the expressions. Decimals in the expressions are truncated, not rounded.
Syntax
```
expression * expression
```
Both expressions must be integers.
## DB parameter functions
You specify the arguments of DB parameter functions as either integers or formulas. Each function must have at least one argument. Specify multiple arguments as a comma-separated list. The list can't have any empty members, such as *argument1*,,*argument3*. Function names are case-insensitive.
*IF*
Returns an argument.
Syntax
```
IF(argument1, argument2, argument3)
```
Returns the second argument if the first argument evaluates to true. Returns the third argument otherwise.
*GREATEST*
Returns the largest value from a list of integers or parameter formulas.
Syntax
```
GREATEST(argument1, argument2,...argumentn)
```
Returns an integer.
*LEAST*
Returns the smallest value from a list of integers or parameter formulas.
Syntax
```
LEAST(argument1, argument2,...argumentn)
```
Returns an integer.
*SUM*
Adds the values of the specified integers or parameter formulas.
Syntax
```
SUM(argument1, argument2,...argumentn)
```
Returns an integer.
## DB parameter log expressions
You can set an integer DB parameter value to a log expression. You enclose the expression in braces: \$1\$1. For example:
```
{log(DBInstanceClassMemory/8187281418)*1000}
```
The `log` function represents log base 2. This example also uses the `DBInstanceClassMemory` formula variable. See [DB parameter formula variables](#USER_FormulaVariables).
## DB parameter value examples
These examples show using formulas, functions, and expressions for the values of DB parameters.
**Warning**
Improperly setting parameters in a DB parameter group can have unintended adverse effects. These might include degraded performance and system instability. Use caution when modifying database parameters and back up your data before modifying your DB parameter group. Try out parameter group changes on a test DB instance, created using point-in-time-restores, before applying those parameter group changes to your production DB instances.
**Example using the DB parameter function LEAST**
You can specify the `LEAST` function in an Aurora MySQL `table_definition_cache` parameter value. Use it to set the number of table definitions that can be stored in the definition cache to the lesser of `DBInstanceClassMemory`/393040 or 20,000.
```
LEAST({DBInstanceClassMemory/393040}, 20000)
```