I am trying to use the magento-cloud cli and getting the following error when i try to use the
`magento-cloud db:size` command.

```
vagrant@ubuntu-bionic:~$ magento-cloud db:size
Enter a number to choose a project:
  [0] Project SMC(dbname)
 > 0

Enter a number to choose an environment:
Default: master
  [0] Integration (integration)
  [1] Master (master)
  [3] Production (production)
 > 3

Enter a number to choose a relationship:
  [0] database (dbname)
  [1] database-ro (dbname_ro)
  [2] database-slave (dbslavename)
 > 0

Checking database service mysql...

  [ProcessFailedException]                                                                                                                                   
  The command failed with the exit code: 1                                                                                                                   

  Full command: ssh '-o' 'SendEnv TERM' '-o' 'CertificateFile /home/vagrant/.magento-cloud/.session/sess-cli-default/ssh/id_ed25519-cert.pub' '-o' 'Identit  
  yFile /home/vagrant/.magento-cloud/.session/sess-cli-default/ssh/id_ed25519' 'user.ssh@ssh.eu-3.magento.cloud' 'mysql --user=  
  '\''username'\'' --password='\''pass'\'' --host='\''127.0.0.1'\'' --port=3306 --no-auto-rehash --raw --skip-column-names' 

```

Any ideas why it is happening? Is there a possibility that it is due to a read-only user?