The IDBObjectStoreSync interface of the IndexedDB API provides synchronous access to an object store of a database.
The IDBVersionChangeRequest interface the IndexedDB API represents a request to change the version of a database. It is used only by the setVersion() method of IDBDatabase.
The NamedNodeMap interface represents a collection of Attr objects. Objects inside a NamedNodeMap are not in any particular order, unlike NodeList, although they may be accessed by an index as in an array.