Method: Mongo::Collection#create_index

Defined in:

lib/jmongo/collection.rb

#create_index(spec, opts = {}) ⇒ String

Create a new index.

Examples:

Creating a compound index:

@posts.create_index([['subject', Mongo::ASCENDING], ['created_at', Mongo::DESCENDING]])

Creating a geospatial index:

@restaurants.create_index([['location', Mongo::GEO2D]])

# Note that this will work only if 'location' represents x,y coordinates:
{'location': [0, 50]}
{'location': {'x' => 0, 'y' => 50}}
{'location': {'latitude' => 0, 'longitude' => 50}}

A geospatial index with alternate longitude and latitude:

@restaurants.create_index([['location', Mongo::GEO2D]], :min => 500, :max => 500)

Parameters:

• spec (String, Array) —

  should be either a single field name or an array of

  field name, direction

  pairs. Directions should be specified

  as Mongo::ASCENDING, Mongo::DESCENDING, or Mongo::GEO2D.

  Note that geospatial indexing only works with versions of MongoDB >= 1.3.3+. Keep in mind, too, that in order to geo-index a given field, that field must reference either an array or a sub-object where the first two values represent x- and y-coordinates. Examples can be seen below.

  Also note that it is permissible to create compound indexes that include a geospatial index as long as the geospatial index comes first.

• unique (Boolean) —

  if true, this index will enforce a uniqueness constraint. DEPRECATED. Future versions of this driver will specify the uniqueness constraint using a hash param.

• opts (Hash) (defaults to: {}) —

  a customizable set of options

Options Hash (opts):

• :unique (Boolean) — default: false —

  if true, this index will enforce a uniqueness constraint.

• :background (Boolean) — default: false —

  indicate that the index should be built in the background. This feature is only available in MongoDB >= 1.3.2.

• :dropDups (Boolean) —

  If creating a unique index on a collection with pre-existing records, this option will keep the first document the database indexes and drop all subsequent with duplicate values.

• :min (Integer) —

  specify the minimum longitude and latitude for a geo index.

• :max (Integer) —

  specify the maximum longitude and latitude for a geo index.

Returns:

• (String) —

  the name of the index created.

# File 'lib/jmongo/collection.rb', line 372

def create_index(spec, opts={})
  _create_index(spec, opts)
end