Using Multikeys to Simulate a Large Number of Indexes

One way to work with data that has a high degree of options for queryability is to use the multikey indexing feature where the keys are objects. For example:

> x = {
... _id : "abc",
... cost : 33,
... attribs : [
...          { color : 'red' },
...          { shape : 'rect' },
...          { color : 'blue' },
...          { avail : true } ]
... };
> db.foo.insert(x);
> db.foo.ensureIndex({attribs:1});
> db.foo.find( { attribs : {color:'blue'} } ); // uses index
> db.foo.find( { attribs : {avail:false} } );  // uses index

In addition to being able to have an unlimited number of attributes types, we can also add new types dynamically.

This is mainly useful for simply attribute lookups; the above pattern is not necessary helpful for sorting or certain other query types.

Using Multikeys to Simulate a Large Number of Indexes

See Also

Labels