MAGETWO-48790: Reindex hanging after large import of products

Author: mslabko

app/code/Magento/Catalog/Model/ResourceModel/Product.php

@@ -66,6 +66,11 @@ class Product extends AbstractResource
      */
     protected $defaultAttributes;
 
+    /**
+     * @var array
+     */
+    protected $availableCategoryIdsCache = [];
+
     /**
      * @param \Magento\Eav\Model\Entity\Context $context
      * @param \Magento\Store\Model\StoreManagerInterface $storeManager
@@ -465,18 +470,22 @@ public function getAvailableInCategories($object)
     {
         // is_parent=1 ensures that we'll get only category IDs those are direct parents of the product, instead of
         // fetching all parent IDs, including those are higher on the tree
-        $select = $this->getConnection()->select()->distinct()->from(
-            $this->getTable('catalog_category_product_index'),
-            ['category_id']
-        )->where(
-            'product_id = ? AND is_parent = 1',
-            (int)$object->getEntityId()
-        )->where(
-            'visibility != ?',
-            \Magento\Catalog\Model\Product\Visibility::VISIBILITY_NOT_VISIBLE
-        );
-
-        return $this->getConnection()->fetchCol($select);
+        $entityId = (int)$object->getEntityId();
+        if (!isset($this->availableCategoryIdsCache[$entityId])) {
+            $this->availableCategoryIdsCache[$entityId] = $this->getConnection()->fetchCol(
+                $this->getConnection()->select()->distinct()->from(
+                    $this->getTable('catalog_category_product_index'),
+                    ['category_id']
+                )->where(
+                    'product_id = ? AND is_parent = 1',
+                    $entityId
+                )->where(
+                    'visibility != ?',
+                    \Magento\Catalog\Model\Product\Visibility::VISIBILITY_NOT_VISIBLE
+                )
+            );
+        }
+        return $this->availableCategoryIdsCache[$entityId];
     }
 
     /**