Hi,

    The delegation inheritance inherits only fields and methods are not inherited. It can be useful, when we need to embed a model in our current model without affecting the existing views, but we want to have the fields of inherited objects.

    Any field not found in current model will be taken from the inherited models. You can have multiple inheritance, so that the new table created in DB contains your new fields and fields which delegates the inherited object fields (fields storing IDs from inherited tables.

You can find an example in hr.py in hr module:

class hr_employee(osv.osv):

_name = "hr.employee"

_description = "Employee"

_order = 'name_related'

_inherits = {'resource.resource': "resource_id"}

.................

.................

columns{

'resource_id': fields.many2one('resource.resource', 'Resource', ondelete='cascade', required=True, auto_join=True),

}

Here hr.employee objects inherits resource.resource object by delegation and all fields of resource.resource object are accessible from hr.employee. For each employee a resource record will be created and its foreign key is stored in resource_id. The fields values of resource.resource synchronized with the hr.employee object.

Refer the link also: https://www.odoo.com/documentation/8.0/reference/orm.html#inheritance-and-extension