MySQL create index Error#1089
<p>MySQL create index Error#1089</p>

<p><strong>ERROR 1089 (HY000): Incorrect prefix key; the used key part isn't a string, the used length is longer than the key part, or the storage engine doesn't support unique prefix keys</strong></p>

<pre><code>CREATE TABLE t3
(
id INT NOT NULL,
name CHAR(30) NOT NULL,
age INT NOT NULL,
info VARCHAR(255),
INDEX MultiIdx(id, name, age(100))
);
</code></pre>

<p>How to fix this error? thank you.</p>