diff --git a/app/code/Magento/Catalog/Model/Indexer/Category/Flat/AbstractAction.php b/app/code/Magento/Catalog/Model/Indexer/Category/Flat/AbstractAction.php
index 8b952ca844bb9..1506ccf6963bf 100644
--- a/app/code/Magento/Catalog/Model/Indexer/Category/Flat/AbstractAction.php
+++ b/app/code/Magento/Catalog/Model/Indexer/Category/Flat/AbstractAction.php
@@ -8,6 +8,9 @@
 
 use Magento\Framework\App\ResourceConnection;
 
+/**
+ * Abstract action class for category flat indexers.
+ */
 class AbstractAction
 {
     /**
@@ -130,7 +133,7 @@ protected function getFlatTableStructure($tableName)
         $table = $this->connection->newTable(
             $tableName
         )->setComment(
-            sprintf("Catalog Category Flat", $tableName)
+            'Catalog Category Flat'
         );
 
         //Adding columns
@@ -378,7 +381,7 @@ protected function getAttributeValues($entityIds, $storeId)
         $linkField = $this->getCategoryMetadata()->getLinkField();
         foreach ($attributesType as $type) {
             foreach ($this->getAttributeTypeValues($type, $entityIds, $storeId) as $row) {
-                if (isset($row[$linkField]) && isset($row['attribute_id'])) {
+                if (isset($row[$linkField], $row['attribute_id'])) {
                     $attributeId = $row['attribute_id'];
                     if (isset($attributes[$attributeId])) {
                         $attributeCode = $attributes[$attributeId]['attribute_code'];
@@ -496,6 +499,8 @@ protected function getTableName($name)
     }
 
     /**
+     * Get category metadata instance.
+     *
      * @return \Magento\Framework\EntityManager\EntityMetadata
      */
     private function getCategoryMetadata()
@@ -509,6 +514,8 @@ private function getCategoryMetadata()
     }
 
     /**
+     * Get skip static columns instance.
+     *
      * @return array
      */
     private function getSkipStaticColumns()
diff --git a/app/code/Magento/Catalog/Model/ResourceModel/Product/LinkedProductSelectBuilderByBasePrice.php b/app/code/Magento/Catalog/Model/ResourceModel/Product/LinkedProductSelectBuilderByBasePrice.php
index 8841b6059c46f..841fe17bdcf05 100644
--- a/app/code/Magento/Catalog/Model/ResourceModel/Product/LinkedProductSelectBuilderByBasePrice.php
+++ b/app/code/Magento/Catalog/Model/ResourceModel/Product/LinkedProductSelectBuilderByBasePrice.php
@@ -11,6 +11,9 @@
 use Magento\Framework\DB\Select;
 use Magento\Store\Model\Store;
 
+/**
+ * Provide Select object for retrieve product id with minimal price.
+ */
 class LinkedProductSelectBuilderByBasePrice implements LinkedProductSelectBuilderInterface
 {
     /**
@@ -69,7 +72,7 @@ public function __construct(
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
      */
     public function build($productId)
     {
@@ -85,7 +88,7 @@ public function build($productId)
                 []
             )->joinInner(
                 [BaseSelectProcessorInterface::PRODUCT_TABLE_ALIAS => $productTable],
-                sprintf('%s.entity_id = link.child_id', BaseSelectProcessorInterface::PRODUCT_TABLE_ALIAS, $linkField),
+                sprintf('%s.entity_id = link.child_id', BaseSelectProcessorInterface::PRODUCT_TABLE_ALIAS),
                 ['entity_id']
             )->joinInner(
                 ['t' => $priceAttribute->getBackendTable()],