Indexes¶
You can define indexes on documents using the index macro. Provide the key for the index along with a direction. For additional options, supply them in a second options hash parameter.
You can define indexes on embedded document fields as well.
You can index on multiple fields and provide direction.
Indexes can be sparse:
Indexes can be run in the background in cases where they may take some time:
For unique indexes that are defined for a column that might already have duplicate values, you can drop the duplicate entries:
For geospatial indexes, make sure the field you are indexing is an Array.
Indexes can be scoped to a specific database.
You can have Mongoid define indexes for you on “foreign key” fields for relational associations. This only works on the relation macro that the foreign key is stored on.
When you want to create the indexes in the database, use the provided rake task.
Mongoid also provides a rake task to delete all secondary indexes.