MC-41647: SKU Search very slow on Admin Panel

Author: Oleksandr Iegorov

app/code/Magento/CatalogSearch/Model/ResourceModel/Search/Collection.php

@@ -303,12 +303,14 @@ protected function _getSearchEntityIdsSql($query, $searchOnlyInCurrentStore = tr
                 //force index statement not implemented in framework
                 // phpcs:ignore Magento2.SQL.RawQuery
                 $select = sprintf(
-                    'SELECT `t1`.`%s` FROM `%s` AS `t1` FORCE INDEX(%s) LEFT JOIN `%s` AS `t2`
+                    'SELECT `t1`.`%s` FROM `%s` AS `t1` FORCE INDEX(%s)
+                        LEFT JOIN `%s` AS `t2` FORCE INDEX(%s)
                         ON %s WHERE %s AND %s AND (%s)',
                     $linkField,
                     $table,
                     $preparedIndexEnforcements[$table],
                     $table,
+                    $preparedIndexEnforcements[$table],
                     $joinCondition,
                     $condition1,
                     $condition2,

dev/tests/integration/testsuite/Magento/Backend/Controller/Adminhtml/IndexTest.php

@@ -9,7 +9,7 @@
 
 /**
  * @magentoAppArea adminhtml
- * @magentoDbIsolation disabled
+ * @magentoDbIsolation enabled
  */
 class IndexTest extends \Magento\TestFramework\TestCase\AbstractBackendController
 {