Extracting database structure from classes Local_group, Location_namespace and Login_token
Extracting database structure from class Message
Extracting database structure from classes Nonce, Notice, Notice_source and Notice_tag
Extracting database structure from classes Oauth_application, Oauth_application_user, Oauth_token_association and Old_school_prefs
schemaDef must return an Array (json_decode returns an objet by default)