diff --git a/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php b/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php
index b1294339e6..0866762f27 100644
--- a/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php
+++ b/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php
@@ -3,6 +3,7 @@
 namespace Drupal\migrate\Plugin\migrate\id_map;
 
 use Drupal\Core\Database\DatabaseException;
+use Drupal\Core\Database\DatabaseExceptionWrapper;
 use Drupal\Core\Field\BaseFieldDefinition;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Plugin\PluginBase;
@@ -591,7 +592,16 @@ public function lookupDestinationIds(array $source_id_values) {
       }
     }
 
-    return $query->execute()->fetchAll(\PDO::FETCH_NUM);
+    try {
+      return $query->execute()->fetchAll(\PDO::FETCH_NUM);
+    }
+    catch (DatabaseExceptionWrapper $e) {
+      // It's possible that the query will cause an exception to be thrown. For
+      // example, the URL alias migration uses a dummy node ID of 'INVALID_NID'
+      // to cause the lookup to return no results. On PostgreSQL this causes an
+      // exception because 'INVALID_NID' is not the expected type.
+      return [];
+    }
   }
 
   /**
diff --git a/core/modules/migrate_drupal/tests/src/Traits/NodeMigrateTypeTestTrait.php b/core/modules/migrate_drupal/tests/src/Traits/NodeMigrateTypeTestTrait.php
index a5eded5d31..21cba11551 100644
--- a/core/modules/migrate_drupal/tests/src/Traits/NodeMigrateTypeTestTrait.php
+++ b/core/modules/migrate_drupal/tests/src/Traits/NodeMigrateTypeTestTrait.php
@@ -67,7 +67,10 @@ protected function removeNodeMigrateMapTable($type, $version) {
    */
   protected function getTableName($type, $version) {
     if (!$this->tableName) {
-      $content_type = $this->randomMachineName();
+      // PostgreSQL table names are automatically converted lowercase. If this
+      // string is not lowercase then we can't remove the table in
+      // \Drupal\Tests\migrate_drupal\Traits\NodeMigrateTypeTestTrait::removeNodeMigrateMapTable().
+      $content_type = strtolower($this->randomMachineName());
       $this->tableName = 'migrate_map_d' . $version . '_node_complete__' . $content_type;
       if ($type == NodeMigrateType::NODE_MIGRATE_TYPE_CLASSIC) {
         $this->tableName = 'migrate_map_d' . $version . '_node__' . $content_type;
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeCompleteTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeCompleteTest.php
index 1e769653c7..704d7eb230 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeCompleteTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeCompleteTest.php
@@ -62,10 +62,15 @@ public function testNodeCompleteMigration() {
     $db = \Drupal::database();
     $this->assertEquals($this->expectedNodeFieldRevisionTable(), $db->select('node_field_revision', 'nr')
       ->fields('nr')
+      ->orderBy('vid')
+      ->orderBy('langcode')
       ->execute()
       ->fetchAll(\PDO::FETCH_ASSOC));
     $this->assertEquals($this->expectedNodeFieldDataTable(), $db->select('node_field_data', 'nr')
       ->fields('nr')
+      ->orderBy('nid')
+      ->orderBy('vid')
+      ->orderBy('langcode')
       ->execute()
       ->fetchAll(\PDO::FETCH_ASSOC));
 
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeCompleteTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeCompleteTest.php
index 59021cabfa..6525de07af 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeCompleteTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeCompleteTest.php
@@ -107,10 +107,15 @@ public function testNodeCompleteMigration() {
     $db = \Drupal::database();
     $this->assertEquals($this->expectedNodeFieldRevisionTable(), $db->select('node_field_revision', 'nr')
       ->fields('nr')
+      ->orderBy('vid')
+      ->orderBy('langcode')
       ->execute()
       ->fetchAll(\PDO::FETCH_ASSOC));
     $this->assertEquals($this->expectedNodeFieldDataTable(), $db->select('node_field_data', 'nr')
       ->fields('nr')
+      ->orderBy('nid')
+      ->orderBy('vid')
+      ->orderBy('langcode')
       ->execute()
       ->fetchAll(\PDO::FETCH_ASSOC));