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
```
odoo/models.py
result.append(command[2])
            elif command[0] == 1:
                record_ids.append(command[1])
                updates[command[1]].update(command[2])
            elif command[0] in (2, 3):
                record_ids = [id for id in record_ids if id != command[1]]
            elif command[0] == 4:
                record_ids.append(command[1])
            elif command[0] == 5:
                result, record_ids = [], []
            elif command[0] == 6:
                result, record_ids = [], list(command[2])
        
        field = self._fields[field_name]
        records = self.env[field.comodel_name].browse(record_ids)
        for data in records.read(fields):
            data.update(updates.get(data['id'], {}))
            result.append(data)
        return result
    
    resolve_o2m_commands_to_record_dicts = resolve_2many_commands
    @api.model
    def search_read(self, domain=None, fields=None, offset=0, limit=None, order=None):
        """
        Performs a ``search()`` followed by a ``read()``.
        :param domain: Search domain, see ``args`` parameter in ``search()``. Defaults to an empty domain that will match all records.
        :param fields: List of fields to read, see ``fields`` parameter in ``read()``. Defaults to all fields.
        :param offset: Number of records to skip, see ``offset`` parameter in ``search()``. Defaults to 0.
        :param limit: Maximum number of records to return, see ``limit`` parameter in ``search()``. Defaults to no limit.
        :param order: Columns to sort result, see ``order`` parameter in ``search()``. Defaults to no sort.