Question

How can I query the data in cassandra OR riak if the value of a key in the object is a List

example=>
Genre[Key] : Pop, rock [Values]

I want to list all songs with the genre rock and so on.

Can I do this using Cassandra/Riak’s secondary indexes?

Answer 1

Yes, Riak’s secondary indexes can handle this for you.

You would simply store your objects in Riak and index them with the appropriate genre(s).

Pretend your data looks like this (JSON):

{ "song":"My awesome song", "genres":["rock", "alternative"] }

You would store the object and use binary indexes for the genres (example using curl):

curl -v -X PUT \
-d '{ "song":"My awesome song", "genres":["rock", "alternative"] }' \
-H "Content-Type: application/json" \
-H "x-riak-index-genre_bin: rock" \
-H "x-riak-index-genre_bin: alternative" \
http://127.0.0.1:8098/riak/mybucket/mykey1

To get all songs indexed with “rock” you’d then do:

curl http://127.0.0.1:8098/buckets/mybucket/index/genre_bin/rock