%wget http://derickrethans.nl/files/dump/mongo-exercise2.php.txt% Open it in your favourite editor and edit. createIndex( [ 'tags_indexed' => 1 ] ); $d->createIndex( [ 'tags_indexed.k' => 1, 'tags_indexed.v' => 1 ] ); var_dump($d->getIndexInfo()); ]]> Run the script!