Think about the data schema!
$doc = array(
'name' => 'A440',
'tags' => [
'highway' => 'secondary',
'oneway' => 'yes'
]
);
$db->poi->ensureIndex( [ 'name' => 1 ] );
$db->poi->ensureIndex( [ 'tags.highway' => 1 ] );
$db->poi->ensureIndex( [ 'tags.oneway' => 1 ] );
// Road with name=Strand
$db->poi->find( [ 'name' => 'Strand' ] );
// All roads
$db->poi->find( [ 'tags.highway' => [ '$exists' => 1 ] ] );
Lots of indexes are required
Easy to extract data from
or:
$doc = array(
'tags' => [
[ 'k' => 'name', 'v' => 'A440' ],
[ 'k' => 'highway', 'v' => 'secondary' ],
[ 'k' => 'oneway', 'v' => 'yes' ]
]
);
$db->poi->ensureIndex( [ 'tags.v' => 1, 'tags.k' => 1 ] );
// Road with name=Strand
$db->poi->find( [
'tags' => [ '$elemMatch' => [ 'k' : 'name', 'v' : 'Strand' ] ]
] );
// All roads
$db->poi->find( [ 'tags.k' => 'highway' ] );
One index required
Good for finding key/value combinations
Extra index needed for "all roads" question (on %tags_indexed.k%)
or:
$doc = array(
'tags' => [
'name=A440',
'highway=secondary',
'oneway=yes'
]
);
$db->poi->ensureIndex( [ 'tags' => 1 ] );
// Road with name=Strand
$db->poi->find( [ 'tags' => 'name=Strand' ] );
// All roads
$db->poi->find( [ 'tags' => new MongoRegex( '/^highway=/' ) ] );
One index required
Good for finding key/value combinations
Good enough for doing the "all roads" question