I have a large table with user votes. I tried nearly every tutorial and essay about INDEX usage and after failing that ... every possible combination of fields as keys, but the query stays slow.

Is there any Index I can use to speed this up?

(I will spare you my hidious attempts at indizes so far...)

```
CREATE TABLE IF NOT EXISTS `votes` (
    `uid` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
    `objectId` bigint(15) NOT NULL,
    `vote` tinyint(1) NOT NULL,
    `created` datetime NOT NULL,
  UNIQUE KEY `unique input` (`uid`,`objectId`),
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

```

The table has around 1.3Million rows and will continue growing. This is the query i am trying:

```
EXPLAIN SELECT objectId, COUNT(uid) AS voteCount, AVG(vote) AS rating
FROM votes
GROUP BY objectId

```

Any pointers?