是的，在AWS数据库中可以同时使用集群数据库和非集群数据库。下面是代码示例：

使用集群数据库：

import boto3

# Create a DocumentDB cluster
client = boto3.client('docdb', region_name='us-east-1')
response = client.create_db_cluster(
    DBClusterIdentifier='my-docdb-cluster',
    Engine='docdb',
    EngineVersion='3.6.0',
    MasterUsername='admin',
    MasterUserPassword='myadminpassword',
    VpcSecurityGroupIds=['sg-12345678'],
    AvailabilityZones=['us-east-1a', 'us-east-1b']
)

# Create a DocumentDB cluster instance
response = client.create_db_instance(
    DBInstanceIdentifier='my-docdb-instance',
    DBInstanceClass='db.t3.medium',
    Engine='docdb',
    EngineVersion='3.6.0',
    DBClusterIdentifier='my-docdb-cluster',
    AvailabilityZone='us-east-1a',
    PubliclyAccessible=True,
    AutoMinorVersionUpgrade=True
)

使用非集群数据库：

import boto3

# Create a MySQL RDS instance
client = boto3.client('rds', region_name='us-east-1')
response = client.create_db_instance(
    DBInstanceIdentifier='my-rds-instance',
    Engine='mysql',
    DBInstanceClass='db.t3.medium',
    MasterUsername='admin',
    MasterUserPassword='mypassword',
    AllocatedStorage=20,
    VpcSecurityGroupIds=['sg-12345678'],
    AvailabilityZone='us-east-1a',
    PubliclyAccessible=True,
    AutoMinorVersionUpgrade=True
)