How to create a model in Odoo without a table in the database

There are cases when is needed to have a model that will not be represented by a table in the database. By default, Odoo creates a table for every Modeland TransientModel​,  but, there is option to change that by setting up the attribute _auto​ to False  

For example, If we want to create a new model PartnerContact​ that will have the base fields and methods for our PartnerCompany and PartnerPerson models the base definition of the model should look like: 

from odoo import models
class PartnerContact(models.Model): _name = '' _description = 'Partner Contact'
_auto = False

Another way of doing this is by inheriting the class AbstractModel which by default has the attribute _auto set to False​​

from odoo import models
class PartnerContact(models.AbstractModel): _name = ''
_description = 'Partner Contact'