diff -u b/core/modules/system/src/Tests/Database/SchemaTest.php b/core/modules/system/src/Tests/Database/SchemaTest.php
--- b/core/modules/system/src/Tests/Database/SchemaTest.php
+++ b/core/modules/system/src/Tests/Database/SchemaTest.php
@@ -67,18 +67,20 @@
     // Assert that the column comment has been set.
     $this->checkSchemaComment($table_specification['fields']['test_field']['description'], 'test_table', 'test_field');
 
-    // Make sure that varchar fields have the correct collation.
-    $columns = db_query('SHOW FULL COLUMNS FROM {test_table}');
-    foreach ($columns as $column) {
-      if ($column->Field == 'test_field_string') {
-        $string_check = ($column->Collation == 'utf8_general_ci');
-      }
-      if ($column->Field == 'test_field_string_ascii') {
-        $string_ascii_check = ($column->Collation == 'ascii_general_ci');
+    if (Database::getConnection()->databaseType() == 'mysql') {
+      // Make sure that varchar fields have the correct collation.
+      $columns = db_query('SHOW FULL COLUMNS FROM {test_table}');
+      foreach ($columns as $column) {
+        if ($column->Field == 'test_field_string') {
+          $string_check = ($column->Collation == 'utf8_general_ci');
+        }
+        if ($column->Field == 'test_field_string_ascii') {
+          $string_ascii_check = ($column->Collation == 'ascii_general_ci');
+        }
       }
+      $this->assertTrue(!empty($string_check), 'string field has the right collation.');
+      $this->assertTrue(!empty($string_ascii_check), 'ASCII string field has the right collation.');
     }
-    $this->assertTrue(!empty($string_check), 'string field has the right collation.');
-    $this->assertTrue(!empty($string_ascii_check), 'ASCII string field has the right collation.');
 
     // An insert without a value for the column 'test_table' should fail.
     $this->assertFalse($this->tryInsert(), 'Insert without a default failed.');