diff --git a/app/code/Magento/Backend/Block/System/Store/Delete/Group.php b/app/code/Magento/Backend/Block/System/Store/Delete/Group.php
index ae80b56066a6d..e95f3bbf9f8c1 100644
--- a/app/code/Magento/Backend/Block/System/Store/Delete/Group.php
+++ b/app/code/Magento/Backend/Block/System/Store/Delete/Group.php
@@ -19,7 +19,7 @@ protected function _prepareLayout()
     {
         $itemId = $this->getRequest()->getParam('group_id');
 
-        $this->setTemplate('system/store/delete_group.phtml');
+        $this->setTemplate('Magento_Backend::system/store/delete_group.phtml');
         $this->setAction($this->getUrl('adminhtml/*/deleteGroupPost', ['group_id' => $itemId]));
         $this->addChild(
             'confirm_deletion_button',
diff --git a/app/code/Magento/Backend/Block/System/Store/Delete/Website.php b/app/code/Magento/Backend/Block/System/Store/Delete/Website.php
index da28a471130cc..82cbb780137b8 100644
--- a/app/code/Magento/Backend/Block/System/Store/Delete/Website.php
+++ b/app/code/Magento/Backend/Block/System/Store/Delete/Website.php
@@ -19,7 +19,7 @@ protected function _prepareLayout()
     {
         $itemId = $this->getRequest()->getParam('website_id');
 
-        $this->setTemplate('system/store/delete_website.phtml');
+        $this->setTemplate('Magento_Backend::system/store/delete_website.phtml');
         $this->setAction($this->getUrl('adminhtml/*/deleteWebsitePost', ['website_id' => $itemId]));
         $this->addChild(
             'confirm_deletion_button',
diff --git a/app/code/Magento/Catalog/Block/Adminhtml/Category/Checkboxes/Tree.php b/app/code/Magento/Catalog/Block/Adminhtml/Category/Checkboxes/Tree.php
index ad1ccea6f2c5a..1e0015d2be2c6 100644
--- a/app/code/Magento/Catalog/Block/Adminhtml/Category/Checkboxes/Tree.php
+++ b/app/code/Magento/Catalog/Block/Adminhtml/Category/Checkboxes/Tree.php
@@ -30,7 +30,7 @@ class Tree extends \Magento\Catalog\Block\Adminhtml\Category\Tree
      */
     protected function _prepareLayout()
     {
-        $this->setTemplate('catalog/category/checkboxes/tree.phtml');
+        $this->setTemplate('Magento_Catalog::catalog/category/checkboxes/tree.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tab/Ajax/Serializer.php b/app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tab/Ajax/Serializer.php
index a7129f509316b..3d131a6e08810 100644
--- a/app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tab/Ajax/Serializer.php
+++ b/app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tab/Ajax/Serializer.php
@@ -41,7 +41,7 @@ public function __construct(
     public function _construct()
     {
         parent::_construct();
-        $this->setTemplate('catalog/product/edit/serializer.phtml');
+        $this->setTemplate('Magento_Catalog::catalog/product/edit/serializer.phtml');
         return $this;
     }
 
diff --git a/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Cart.php b/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Cart.php
index 9ee152078d960..9cd1989980fac 100644
--- a/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Cart.php
+++ b/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Cart.php
@@ -82,7 +82,7 @@ protected function _construct()
         parent::_construct();
         $this->setUseAjax(true);
         $this->_parentTemplate = $this->getTemplate();
-        $this->setTemplate('tab/cart.phtml');
+        $this->setTemplate('Magento_Customer::tab/cart.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Adminhtml/System/Config/Validatevat.php b/app/code/Magento/Customer/Block/Adminhtml/System/Config/Validatevat.php
index 83ce7bef26d60..8cbe5c0680bd3 100644
--- a/app/code/Magento/Customer/Block/Adminhtml/System/Config/Validatevat.php
+++ b/app/code/Magento/Customer/Block/Adminhtml/System/Config/Validatevat.php
@@ -99,7 +99,7 @@ protected function _prepareLayout()
     {
         parent::_prepareLayout();
         if (!$this->getTemplate()) {
-            $this->setTemplate('system/config/validatevat.phtml');
+            $this->setTemplate('Magento_Customer::system/config/validatevat.phtml');
         }
         return $this;
     }
diff --git a/app/code/Magento/Customer/Block/Widget/Company.php b/app/code/Magento/Customer/Block/Widget/Company.php
index 4b928805fa543..d1c86d19a9849 100644
--- a/app/code/Magento/Customer/Block/Widget/Company.php
+++ b/app/code/Magento/Customer/Block/Widget/Company.php
@@ -69,7 +69,7 @@ public function _construct()
         parent::_construct();
 
         // default template location
-        $this->setTemplate('widget/company.phtml');
+        $this->setTemplate('Magento_Customer::widget/company.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Widget/Dob.php b/app/code/Magento/Customer/Block/Widget/Dob.php
index 1a1d5d81bf13d..936563d519823 100644
--- a/app/code/Magento/Customer/Block/Widget/Dob.php
+++ b/app/code/Magento/Customer/Block/Widget/Dob.php
@@ -66,7 +66,7 @@ public function __construct(
     public function _construct()
     {
         parent::_construct();
-        $this->setTemplate('widget/dob.phtml');
+        $this->setTemplate('Magento_Customer::widget/dob.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Widget/Fax.php b/app/code/Magento/Customer/Block/Widget/Fax.php
index 2ede51f0eec96..a775c447142df 100644
--- a/app/code/Magento/Customer/Block/Widget/Fax.php
+++ b/app/code/Magento/Customer/Block/Widget/Fax.php
@@ -69,7 +69,7 @@ public function _construct()
         parent::_construct();
 
         // default template location
-        $this->setTemplate('widget/fax.phtml');
+        $this->setTemplate('Magento_Customer::widget/fax.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Widget/Gender.php b/app/code/Magento/Customer/Block/Widget/Gender.php
index 1d3730e6c6d58..d03c64a54fb94 100644
--- a/app/code/Magento/Customer/Block/Widget/Gender.php
+++ b/app/code/Magento/Customer/Block/Widget/Gender.php
@@ -59,7 +59,7 @@ public function __construct(
     public function _construct()
     {
         parent::_construct();
-        $this->setTemplate('widget/gender.phtml');
+        $this->setTemplate('Magento_Customer::widget/gender.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Widget/Name.php b/app/code/Magento/Customer/Block/Widget/Name.php
index 35f3bbefb8f00..f70ddcd67af3a 100644
--- a/app/code/Magento/Customer/Block/Widget/Name.php
+++ b/app/code/Magento/Customer/Block/Widget/Name.php
@@ -62,7 +62,7 @@ public function _construct()
         parent::_construct();
 
         // default template location
-        $this->setTemplate('widget/name.phtml');
+        $this->setTemplate('Magento_Customer::widget/name.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Widget/Taxvat.php b/app/code/Magento/Customer/Block/Widget/Taxvat.php
index e695681ad4a6c..e5c9c01dc3ac5 100644
--- a/app/code/Magento/Customer/Block/Widget/Taxvat.php
+++ b/app/code/Magento/Customer/Block/Widget/Taxvat.php
@@ -41,7 +41,7 @@ public function __construct(
     public function _construct()
     {
         parent::_construct();
-        $this->setTemplate('widget/taxvat.phtml');
+        $this->setTemplate('Magento_Customer::widget/taxvat.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Customer/Block/Widget/Telephone.php b/app/code/Magento/Customer/Block/Widget/Telephone.php
index b0d155eff6db5..86608ec729b70 100644
--- a/app/code/Magento/Customer/Block/Widget/Telephone.php
+++ b/app/code/Magento/Customer/Block/Widget/Telephone.php
@@ -69,7 +69,7 @@ public function _construct()
         parent::_construct();
 
         // default template location
-        $this->setTemplate('widget/telephone.phtml');
+        $this->setTemplate('Magento_Customer::widget/telephone.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Dhl/Block/Adminhtml/Unitofmeasure.php b/app/code/Magento/Dhl/Block/Adminhtml/Unitofmeasure.php
index deeb769c808fa..bf94a3b5c89ad 100644
--- a/app/code/Magento/Dhl/Block/Adminhtml/Unitofmeasure.php
+++ b/app/code/Magento/Dhl/Block/Adminhtml/Unitofmeasure.php
@@ -86,7 +86,7 @@ public function _construct()
             )
         );
 
-        $this->setTemplate('unitofmeasure.phtml');
+        $this->setTemplate('Magento_Dhl::unitofmeasure.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Paypal/Block/Iframe.php b/app/code/Magento/Paypal/Block/Iframe.php
index 98fc05d0d2f60..bcdfae6b86dbe 100644
--- a/app/code/Magento/Paypal/Block/Iframe.php
+++ b/app/code/Magento/Paypal/Block/Iframe.php
@@ -110,13 +110,13 @@ protected function _construct()
         if (in_array($paymentCode, $this->_hssHelper->getHssMethods())) {
             $this->_paymentMethodCode = $paymentCode;
             $templatePath = str_replace('_', '', $paymentCode);
-            $templateFile = "{$templatePath}/iframe.phtml";
+            $templateFile = "Magento_Paypal::{$templatePath}/iframe.phtml";
             $directory = $this->readFactory->create($this->reader->getModuleDir('', 'Magento_Paypal'));
             $file = $this->resolver->getTemplateFileName($templateFile, ['module' => 'Magento_Paypal']);
             if ($file && $directory->isExist($directory->getRelativePath($file))) {
                 $this->setTemplate($templateFile);
             } else {
-                $this->setTemplate('hss/iframe.phtml');
+                $this->setTemplate('Magento_Paypal::hss/iframe.phtml');
             }
         }
     }
@@ -198,7 +198,7 @@ protected function _beforeToHtml()
     protected function _toHtml()
     {
         if ($this->_isAfterPaymentSave()) {
-            $this->setTemplate('hss/js.phtml');
+            $this->setTemplate('Magento_Paypal::hss/js.phtml');
             return parent::_toHtml();
         }
         if (!$this->_shouldRender) {
diff --git a/app/code/Magento/Review/Block/Form.php b/app/code/Magento/Review/Block/Form.php
index 440e13deb5839..c6dfad8265ac7 100644
--- a/app/code/Magento/Review/Block/Form.php
+++ b/app/code/Magento/Review/Block/Form.php
@@ -139,7 +139,7 @@ protected function _construct()
             );
         }
 
-        $this->setTemplate('form.phtml');
+        $this->setTemplate('Magento_Review::form.phtml');
     }
 
     /**
diff --git a/app/code/Magento/Review/Block/Rating/Entity/Detailed.php b/app/code/Magento/Review/Block/Rating/Entity/Detailed.php
index 0ce4f436ae704..eee00483ace66 100644
--- a/app/code/Magento/Review/Block/Rating/Entity/Detailed.php
+++ b/app/code/Magento/Review/Block/Rating/Entity/Detailed.php
@@ -49,7 +49,7 @@ protected function _toHtml()
         $reviewsCount = $this->_ratingFactory->create()->getTotalReviews($entityId, true);
         if ($reviewsCount == 0) {
             #return __('Be the first to review this product');
-            $this->setTemplate('empty.phtml');
+            $this->setTemplate('Magento_Review::empty.phtml');
             return parent::_toHtml();
         }
 
diff --git a/app/code/Magento/UrlRewrite/Block/Edit.php b/app/code/Magento/UrlRewrite/Block/Edit.php
index baee8af893083..210ed5189eb4c 100644
--- a/app/code/Magento/UrlRewrite/Block/Edit.php
+++ b/app/code/Magento/UrlRewrite/Block/Edit.php
@@ -65,7 +65,7 @@ public function __construct(
      */
     protected function _prepareLayout()
     {
-        $this->setTemplate('edit.phtml');
+        $this->setTemplate('Magento_UrlRewrite::edit.phtml');
 
         $this->_addBackButton();
         $this->_prepareLayoutFeatures();
diff --git a/app/code/Magento/User/Block/Role/Tab/Users.php b/app/code/Magento/User/Block/Role/Tab/Users.php
index d93e7ad63e354..a95a68cbe14f3 100644
--- a/app/code/Magento/User/Block/Role/Tab/Users.php
+++ b/app/code/Magento/User/Block/Role/Tab/Users.php
@@ -45,7 +45,7 @@ protected function _construct()
         $roleId = $this->getRequest()->getParam('rid', false);
         /** @var \Magento\User\Model\ResourceModel\User\Collection $users */
         $users = $this->_userCollectionFactory->create()->load();
-        $this->setTemplate('role/users.phtml')
+        $this->setTemplate('Magento_User::role/users.phtml')
              ->assign('users', $users->getItems())
              ->assign('roleId', $roleId);
     }
diff --git a/lib/internal/Magento/Framework/Search/Adapter/Mysql/Adapter.php b/lib/internal/Magento/Framework/Search/Adapter/Mysql/Adapter.php
index 098782b4e814e..d64f15058393d 100644
--- a/lib/internal/Magento/Framework/Search/Adapter/Mysql/Adapter.php
+++ b/lib/internal/Magento/Framework/Search/Adapter/Mysql/Adapter.php
@@ -7,7 +7,6 @@
 
 use Magento\Framework\App\ResourceConnection;
 use Magento\Framework\DB\Ddl\Table;
-use Magento\Framework\DB\Select;
 use Magento\Framework\Search\Adapter\Mysql\Aggregation\Builder as AggregationBuilder;
 use Magento\Framework\Search\AdapterInterface;
 use Magento\Framework\Search\RequestInterface;