[PERF] product: Improve name_search performance

Issue:
The name_search performance was highly inefficient with a high number of
records.

Analyze:
The bottleneck came from the NOT IN search on the product_template.

Fix:
As a NOT IN  is not efficient, an not exists must be used.

Note:
The ORM has to be bypassed has no "not exists" feature has been
implemented yet.

Benchmark:
| # Input data | Before PR | After PR |
|:-------------:|:----------:|:---------:|
| 182386                    |     15+ min           |   ~100 ms |
|       29            |      ~29 ms          |    ~28 ms           |

Related task:
opw-3554133

closes odoo/odoo#145095

X-original-commit: 955d28a485d569569af2792fa014b52c1829d178
Signed-off-by: Benjamin Hanquin (beha) <beha@odoo.com>

addons/product/models/product_template.py

@@ -546,14 +546,22 @@ class ProductTemplate(models.Model):
         searched_ids = set(templates.ids)
         # some product.templates do not have product.products yet (dynamic variants configuration),
         # we need to add the base _name_search to the results
-        # FIXME awa: this is really not performant at all but after discussing with the team
-        # we don't see another way to do it
-        tmpl_without_variant = self.browse()
-        if not limit or len(searched_ids) < limit:
-            tmpl_with_variant_ids = self._search([('product_variant_ids.active', '=', True)])
-            tmpl_without_variant = self.search([('id', 'not in', tmpl_with_variant_ids)])
-        if tmpl_without_variant:
-            domain2 = expression.AND([domain, [('id', 'in', tmpl_without_variant.ids)]])
+        tmpl_without_variant_ids = []
+        # Useless if variants is not set up as no tmpl_without_variant_ids could exist.
+        if self.env.user.has_group('product.group_product_variant') and (not limit or len(searched_ids) < limit):
+            # The ORM has to be bypassed because it would require a NOT IN which is inefficient.
+            self.env['product.product'].flush_model(['product_tmpl_id', 'active'])
+            tmpl_without_variant_ids = self.env['product.template']._search([], order='id')
+            tmpl_without_variant_ids.add_where("""
+                NOT EXISTS (
+                    SELECT product_tmpl_id
+                    FROM product_product
+                    WHERE product_product.active = true
+                        AND product_template.id = product_product.product_tmpl_id
+                )
+            """)
+        if tmpl_without_variant_ids:
+            domain2 = expression.AND([domain, [('id', 'in', tmpl_without_variant_ids)]])
             searched_ids |= set(super()._name_search(name, domain2, operator, limit, order))
 
         # re-apply product.template order + display_name

addons/product/tests/test_name.py

@@ -29,3 +29,28 @@ class TestName(TransactionCase):
         res = self.env['product.template'].name_search(name='PTN', operator='not ilike')
         res_ids = [r[0] for r in res]
         self.assertNotIn(self.product.id, res_ids)
+
+    def test_product_template_search_name_no_product_product(self):
+        color_attr = self.env['product.attribute'].create({'name': 'Color', 'create_variant': 'dynamic'})
+        color_attr_value_r = self.env['product.attribute.value'].create({'name': 'Red', 'attribute_id': color_attr.id})
+        color_attr_value_b = self.env['product.attribute.value'].create({'name': 'Blue', 'attribute_id': color_attr.id})
+        template_dyn = self.env['product.template'].create({
+            'name': 'Test Dynamical',
+            'attribute_line_ids': [(0, 0, {
+                'attribute_id': color_attr.id,
+                'value_ids': [(4, color_attr_value_r.id), (4, color_attr_value_b.id)],
+            })]
+        })
+        product = self.env['product.product'].create({
+            'name': 'Dynamo Lamp',
+            'default_code': 'Dynamo',
+        })
+        self.assertTrue(template_dyn.has_dynamic_attributes())
+        # Ensure that template_dyn hasn't any product_product
+        self.assertEqual(len(template_dyn.product_variant_ids), 0)
+        # Ensure that Dynam search return Dynamo and Test Dynamical as this
+        # last have no product_product
+        res = self.env['product.template'].name_search(name='Dynam', operator='ilike')
+        res_ids = [r[0] for r in res]
+        self.assertIn(template_dyn.id, res_ids)
+        self.assertIn(product.product_tmpl_id.id, res_ids)