Remove target_search on Many2One

trytond/CHANGELOG

@@ -1,3 +1,4 @@
+* Replace target_search by use of count()
 * Manage domain on id in single value list as unique
 * Do not validate domain for empty fields
 * Warn about implicit save() of unsaved relation

trytond/doc/ref/fields.rst

@@ -694,7 +694,7 @@ Instance methods:
 Many2One
 --------
 
-.. class:: Many2One(model_name, string[, left[, right[, path[, ondelete[, datetime_field[, target_search[, search_order[, search_context[, \**options]]]]]]]]])
+.. class:: Many2One(model_name, string[, left[, right[, path[, ondelete[, datetime_field[, search_order[, search_context[, \**options]]]]]]]])
 
    A many-to-one relation field that refers to a record of the named model.
 
@@ -769,23 +769,6 @@ Many2One
    :attr:`~trytond.model.ModelSQL._history` to request a value for a given date
    and time on a historicized model.
 
-.. attribute:: Many2One.target_search
-
-   Define the kind of SQL query to use when searching on related target.
-
-   Allowed values are:
-
-      - ``subquery``: uses a subquery based on the ids.
-
-      - ``join``: adds a join on the main query.
-
-   ``join`` is the default value.
-
-   .. note::
-
-      ``join`` could improve the performance if the target has a huge amount of
-      records.
-
 .. attribute:: Many2One.search_order
 
    A :ref:`PYSON <ref-pyson>` expression defining the default order used to

trytond/doc/topics/configuration.rst

@@ -180,6 +180,13 @@ The number of retries when a database operational error occurs during a request.
 
 Default: ``5``
 
+subquery_threshold
+~~~~~~~~~~~~~~~~~~
+
+The number of records in the target relation under which a sub-query is used.
+
+Default: ``1000``
+
 language
 ~~~~~~~~
 

trytond/trytond/config.py

@@ -64,6 +64,7 @@ class TrytonConfigParser(configparser.ConfigParser):
         self.set('database', 'retry', '5')
         self.set('database', 'language', 'en')
         self.set('database', 'timeout', str(30 * 60))
+        self.set('database', 'subquery_threshold', str(1_000))
         self.add_section('request')
         self.set('request', 'max_size', str(2 * 1024 * 1024))
         self.set('request', 'max_size_authenticated',

trytond/trytond/model/fields/many2one.py

@@ -5,6 +5,7 @@ from sql.aggregate import Max
 from sql.conditionals import Coalesce
 from sql.operators import Or
 
+from trytond.config import config
 from trytond.pool import Pool
 from trytond.pyson import PYSONEncoder
 from trytond.tools import cached_property, reduce_ids
@@ -14,6 +15,8 @@ from .field import (
     Field, context_validate, instantiate_context, search_order_validate,
     with_inactive_records)
 
+_subquery_threshold = config.getint('database', 'subquery_threshold')
+
 
 class Many2One(Field):
     '''
@@ -23,7 +26,7 @@ class Many2One(Field):
     _sql_type = 'INTEGER'
 
     def __init__(self, model_name, string='', left=None, right=None, path=None,
-            ondelete='SET NULL', datetime_field=None, target_search='join',
+            ondelete='SET NULL', datetime_field=None,
             search_order=None, search_context=None, help='', required=False,
             readonly=False, domain=None, states=None,
             on_change=None, on_change_with=None, depends=None, context=None,
@@ -57,8 +60,6 @@ class Many2One(Field):
         self.right = right
         self.path = path
         self.datetime_field = datetime_field
-        assert target_search in ['subquery', 'join']
-        self.target_search = target_search
         self.__search_order = None
         self.search_order = search_order
         self.__search_context = None
@@ -258,7 +259,7 @@ class Many2One(Field):
         else:
             _, target_name = name.split('.', 1)
         target_domain = [(target_name,) + tuple(domain[1:])]
-        if self.target_search == 'subquery':
+        if Target.count() < _subquery_threshold:
             query = Target.search(target_domain, order=[], query=True)
             return column.in_(query)
         else:

trytond/trytond/tests/test_field_many2one.py

@@ -2,6 +2,8 @@
 # this repository contains the full copyright notices and license terms.
 import unittest
 
+from sql import Join
+
 from trytond.model.exceptions import DomainValidationError
 from trytond.pool import Pool
 from trytond.tests.test_tryton import activate_module, with_transaction
@@ -157,7 +159,9 @@ class FieldMany2OneTestCase(unittest.TestCase):
         self.assertListEqual(result, [record])
 
     @with_transaction()
-    def _test_search_join(self, target_search):
+    def _test_search_join(self, subquery_threshold=1_000):
+        from trytond.model.fields import many2one
+
         pool = Pool()
         Target = pool.get('test.many2one_target')
         Many2One = pool.get('test.many2one')
@@ -170,24 +174,28 @@ class FieldMany2OneTestCase(unittest.TestCase):
                 {'many2one': target2},
                 ])
 
-        def set_target_search(target_search):
-            Many2One.many2one.target_search = target_search
-        self.addCleanup(set_target_search, Many2One.many2one.target_search)
-        set_target_search(target_search)
+        previous = many2one._subquery_threshold
+        many2one._subquery_threshold = subquery_threshold
+        self.addCleanup(setattr, many2one, '_subquery_threshold', previous)
 
         many2ones = Many2One.search([
                 ('many2one.value', '=', 1),
                 ])
-
         self.assertListEqual(many2ones, [many2one1])
 
+        return Many2One.search([
+                ('many2one.value', '=', 1),
+                ], query=True)
+
     def test_search_join(self):
         "Test search by many2one join"
-        self._test_search_join('join')
+        query = self._test_search_join(0)
+        self.assertIsInstance(query.from_[0], Join)
 
     def test_search_subquery(self):
         "Test search by many2one subquery"
-        self._test_search_join('subquery')
+        query = self._test_search_join()
+        self.assertNotIsInstance(query.from_[0], Join)
 
     @with_transaction()
     def test_context_attribute(self):