On large recordsets I got some severe performance issues while browsing through an inherits relation.
For example I have a batch process exporting a csv file with products variants:

I have to export 50.000 products.

If I do :
`variant.categ_id` It takes a very long time to get the result.

If I do:
`variant.product_tmpl_id.categ_id` The result is immediate

The problem is that the global perfomance of the application is impacted by this problem.

For example my POS takes more than 15 minutes to load. Because I have 26.000 products and the compute price method uses a lot browsing through the inherits such like `product.cated_id`, `product.uom_id` and they all takes a huge time to compute.

Same issue in this case.

If I do :
`variant.price` It takes a very long time to get the result.

If I do:
`variant.product_tmpl_id.price` The result is immediate

Could you help me ?


Simple way to reproduce:

1/ Create a new database and install sale module
2/ Launch following script through odoo shell :

```python
# -*- coding: utf-8 -*-
import logging

_logger = logging.getLogger(__name__)
self = self  # noqa

nb_product = 50000

i = 0
while i < nb_product:
    prod = self.env['product.template'].create({'name': 'product_%s' % i})
    i += 1
    if i % 1000 == 0:
        self.env.cr.commit()
        _logger.info("%s Products Created" % i)
```

2/ Launch following script through odoo shell :
```python
# -*- coding: utf-8 -*-
import logging

_logger = logging.getLogger(__name__)
self = self  # noqa


products = self.env['product.product'].search([])

for product in products:
    # Immediate response
    _logger.info('Category Template %s' % product.product_tmpl_id.categ_id)
    # Lagging response
    _logger.info('Category Variant %s' % product.categ_id) 
    break
```
def load_views(self, views, options=None):
        """ Returns the fields_views of given views, and optionally filters and fields.
        :param views: list of [view_id, view_type]
        :param options['toolbar']: True to include contextual actions when loading fields_views
        :param options['load_filters']: True to return the model's filters
        :param options['action_id']: id of the action to get the filters
        :param options['load_fields']: True to load the model's fields
        :return: dictionary with fields_views, filters and fields
        """
        options = options or {}
        result = {}
        toolbar = options.get('toolbar')
        result['fields_views'] = {
            v_type: self.fields_view_get(v_id, v_type if v_type != 'list' else 'tree',
                                         toolbar=toolbar if v_type != 'search' else False)
            for [v_id, v_type] in views
        }
        if options.get('load_filters'):
            result['filters'] = self.env['ir.filters'].get_filters(self._name, options.get('action_id'))
        if options.get('load_fields'):
            result['fields'] = self.fields_get()
        return result
    @api.model
    def fields_view_get(self, view_id=None, view_type='form', toolbar=False, submenu=False):
        """ fields_view_get([view_id | view_type='form'])
        Get the detailed composition of the requested view like fields, model, view architecture
        :param view_id: id of the view or None
        :param view_type: type of the view to return if view_id is None ('form', 'tree', ...)
        :param toolbar: true to include contextual actions
        :param submenu: deprecated