When Restoring RDS databases that use parameter groups there are a few things you need to know:

• When you are restoring an RDS database from a snapshot it will try to use the RDS default parameter group when recreating the database. You have the option to select the specific parameter group that you created to work with this database originally. If you do not select the appropriate parameter group at this stage, you can of course do so later, it will just require a restart of the database instance to take effect.
• Another thing to keep in mind is that when moving snapshots across regions, they do not bring the associated parameter group with them. You will need to recreate the group in that region and associate it using the method we just talked about.

Another note is that Amazon Aurora also has the ability to tune parameters just like AmazonRDS. They function in much the same way as we have described early but there are a few differences. Since aurora functions as a group of instances, as a cluster, there are two separate parameters types you can have. There are individual parameters that affect just a single instance within the cluster, and then there are parameters that affect the entire cluster as a whole.

Cluster level parameters are managed within DB cluster parameters groups, while the instance level parameters are maintained by DB parameters groups. You can view both types of parameters within the console and the CLI, and overall they operate much the same as we have discussed for RDS.