$ sudo brew install memcached

$ sudo memcached -m 32 -p 11211 -d

$ sudo phpize

Cannot find autoconf. Please check your autoconf installation and the
$PHP_AUTOCONF environment variable. Then, rerun this script.

$ sudo ./configure
$ sudo make
$ sudo make install

Installing shared extensions: /usr/lib/php/extensions/no-debug-non-zts-xxxxxx/

extension=/usr/lib/php/extensions/no-debug-non-zts-xxxxxx/memcache.so

'components'=>array(

  'cache'=>array(
    'class'=>'CMemCache',
    'servers'=>array(
      array(
        'host'=>'127.0.0.1',
        'port'=>11211
      )
    ),
  ),
...

Yii::app()->cache->set('key1','value1');
Yii::app()->cache->get('key1');

function get_foo (int userid) {
  result = db_select("SELECT * FROM users WHERE userid = ", userid);
  return result;
}

function get_foo (int userid) {
  result = memcached_fetch("userrow:" + userid);
  if (!result) {
    result = db_select("SELECT * FROM users WHERE userid = ", userid);
    memcached_add("userrow:" + userid, result);
  }
  return result;
}

function update_foo(int userid, string dbUpdateString) {
  result = db_execute(dbUpdateString);
  if (result) {
    data = createUserDataFromDBString(dbUpdateString);
    memcached_set("userrow:"+userid, data);
  }
}