MongoDb Collection 300K Objects Making an A to Z page - php

Question

We have a website with about 300,000 people on it - what we want to do is make an page with all the peoples name that starts with A, B, or C.
The challenge is the speed.
How would you set up your database. Do you make a cache collection. Do you use regex or something else.
What i've done is the following;
$letter = 'A';
$where = array();
$where['name'] = new MongoRegex("/^" . $letter . "/i");
$sort = array('name' => 1);
if($hasImage){
$where['images.profiles.0'] = array('$exists' => true);
}
$fields = array('name' => 1, 'images.profiles' => 1);
$this->mdb->data_people->ensureIndex(array('name' => 1, 'images.profiles' => 1), array('background' => true) );
$people = $this->mdb->data_people->find( $where, $fields );
$people = $people->sort( $sort );
$page['total'] = 100;
$page['current'] = 1;
$page['perPage'] = 20;
if(isset($this->domain->getQuery['_page']) && $this->domain->getQuery['_page'] > 1){
$page['current'] = $this->domain->getQuery['_page'];
}
$data['pages'] = $this->pageNavigation->setNavigation((int) $page['total'], (int) $page['perPage'], (int) $page['current'] );
$data['pages']['page'] = $this->domain->menu_reverse[0];
$data['pages']['path'] = $this->domain->path;
$data['data'] = $people->limit($page['perPage'])->skip( ($page['perPage']*($page['current']-1)) );

Answer 1

You are pretty much doing the right thing.
You are even using the right regexp since it look only for the start of the string, and so Mongodb can use the name index.
see bottom of this page: http://docs.mongodb.org/manual/reference/operator/query/regex/)
I see only two potential problems (but as always: don't do premature optimization, you'll code can be just fine as is):
the case-insensitive modifier in the regexp: try using a strtolower-ed field insted (create a nameCanonical field with the lowercase version of the name field.)
the pagination, which is always slow: try using a range-based pagination http://docs.mongodb.org/manual/reference/method/cursor.skip/