[ci skip] Fix #5624
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index f8956f0..c397bb7 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1308,19 +1308,13 @@
 	 */
 	public function list_fields($table)
 	{
-		// Is there a cached result?
-		if (isset($this->data_cache['field_names'][$table]))
-		{
-			return $this->data_cache['field_names'][$table];
-		}
-
 		if (FALSE === ($sql = $this->_list_columns($table)))
 		{
 			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
 
 		$query = $this->query($sql);
-		$this->data_cache['field_names'][$table] = array();
+		$fields = array();
 
 		foreach ($query->result_array() as $row)
 		{
@@ -1342,10 +1336,10 @@
 				}
 			}
 
-			$this->data_cache['field_names'][$table][] = $row[$key];
+			$fields[] = $row[$key];
 		}
 
-		return $this->data_cache['field_names'][$table];
+		return $fields;
 	}
 
 	// --------------------------------------------------------------------