diff -u b/core/modules/aggregator/src/Entity/Feed.php b/core/modules/aggregator/src/Entity/Feed.php
--- b/core/modules/aggregator/src/Entity/Feed.php
+++ b/core/modules/aggregator/src/Entity/Feed.php
@@ -145,9 +145,6 @@
       ->setLabel(t('Title'))
       ->setDescription(t('The name of the feed (or the name of the website providing the feed).'))
       ->setRequired(TRUE)
-      // We have a unique constraint on the title field, which has the utf8mb4
-      // character set in MySQL so we can't have more than 191 characters.
-      ->setSetting('max_length', 191)
       ->setDisplayOptions('form', array(
         'type' => 'string_textfield',
         'weight' => -5,
diff -u b/core/modules/block_content/src/Entity/BlockContent.php b/core/modules/block_content/src/Entity/BlockContent.php
--- b/core/modules/block_content/src/Entity/BlockContent.php
+++ b/core/modules/block_content/src/Entity/BlockContent.php
@@ -22,7 +22,7 @@
  *   bundle_label = @Translation("Custom block type"),
  *   handlers = {
  *     "storage" = "Drupal\Core\Entity\Sql\SqlContentEntityStorage",
- *     "storage_schema" = "Drupal\block_content\BlockContentStorageSchema",
+ *     "storage_schema" = "Drupal\Core\Entity\Sql\SqlContentEntityStorageSchema",
  *     "access" = "Drupal\block_content\BlockContentAccessControlHandler",
  *     "list_builder" = "Drupal\block_content\BlockContentListBuilder",
  *     "view_builder" = "Drupal\block_content\BlockContentViewBuilder",
@@ -187,10 +187,7 @@
         'type' => 'string_textfield',
         'weight' => -5,
       ))
-      ->setDisplayConfigurable('form', TRUE)
-      // We have a unique constraint on the info field, which has the utf8mb4
-      // character set in MySQL so we can't have more than 191 characters.
-      ->setSetting('max_length', 191);
+      ->setDisplayConfigurable('form', TRUE);
 
     $fields['type'] = BaseFieldDefinition::create('entity_reference')
       ->setLabel(t('Block type'))
diff -u b/core/scripts/dump-database-d6.sh b/core/scripts/dump-database-d6.sh
--- b/core/scripts/dump-database-d6.sh
+++ b/core/scripts/dump-database-d6.sh
@@ -52,6 +52,7 @@
 // Get the current schema, order it by table name.
 $schema = drupal_get_schema();
 ksort($schema);
+
 // Override the field type of the filename primary key to bypass the
 // InnoDB 191 character limitation.
 if ($schema['system']['primary key'] == 'filename' && $schema['system']['fields']['filename']['type'] == 'varchar') {
only in patch2:
unchanged:
--- a/core/modules/aggregator/src/FeedStorageSchema.php
+++ b/core/modules/aggregator/src/FeedStorageSchema.php
@@ -33,7 +33,7 @@ protected function getSharedTableFieldSchema(FieldStorageDefinitionInterface $st
           break;
 
         case 'title':
-          $this->addSharedTableFieldUniqueKey($storage_definition, $schema);
+          $this->addSharedTableFieldIndex($storage_definition, $schema);
           break;
       }
     }
only in patch2:
unchanged:
--- a/core/modules/block_content/src/BlockContentStorageSchema.php
+++ /dev/null
@@ -1,52 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\block_content\BlockContentStorageSchema.
- */
-
-namespace Drupal\block_content;
-
-use Drupal\Core\Entity\ContentEntityTypeInterface;
-use Drupal\Core\Entity\Sql\SqlContentEntityStorageSchema;
-use Drupal\Core\Field\FieldStorageDefinitionInterface;
-
-/**
- * Defines the block content schema handler.
- */
-class BlockContentStorageSchema extends SqlContentEntityStorageSchema {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function getEntitySchema(ContentEntityTypeInterface $entity_type, $reset = FALSE) {
-    $schema = parent::getEntitySchema($entity_type, $reset);
-
-    $schema['block_content_field_data']['unique keys'] += array(
-      'block_content__info' => array('info', 'langcode'),
-    );
-
-    return $schema;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function getSharedTableFieldSchema(FieldStorageDefinitionInterface $storage_definition, $table_name, array $column_mapping) {
-    $schema = parent::getSharedTableFieldSchema($storage_definition, $table_name, $column_mapping);
-    $field_name = $storage_definition->getName();
-
-    if ($table_name == 'block_content_field_data') {
-      switch ($field_name) {
-        case 'info':
-          // Improves the performance of the block_content__info index defined
-          // in getEntitySchema().
-          $schema['fields'][$field_name]['not null'] = TRUE;
-          break;
-      }
-    }
-
-    return $schema;
-  }
-
-}
only in patch2:
unchanged:
--- a/core/modules/system/src/Tests/Database/RegressionTest.php
+++ b/core/modules/system/src/Tests/Database/RegressionTest.php
@@ -26,15 +26,15 @@ class RegressionTest extends DatabaseTestBase {
    */
   function testRegression_310447() {
     // That's a 255 character UTF-8 string.
-    $name = str_repeat("é", 255);
+    $job = str_repeat("é", 255);
     db_insert('test')
       ->fields(array(
-        'name' => $name,
+        'name' => $this->randomMachineName(),
         'age' => 20,
-        'job' => 'Dancer',
+        'job' => $job,
       ))->execute();
 
-    $from_database = db_query('SELECT name FROM {test} WHERE name = :name', array(':name' => $name))->fetchField();
+    $from_database = db_query('SELECT job FROM {test} WHERE job = :job', array(':job' => $job))->fetchField();
     $this->assertIdentical($name, $from_database, 'The database handles UTF-8 characters cleanly.');
   }