Do NoSQL databases use or need indexes?

Question

I am a newbie in NoSQL databases and this may sound a bit stupid but I was wondering if NoSQL databases use or need indexes? If yes, how to make or manage them? any links? Thanks

Answer 1

CouchDB and MongoDB definitely yes. I mentioned that in my book:

• http://use-the-index-luke.com/sql/testing-scalability/response-time-throughput-scaling-horizontal

Here are the respective docs:

• http://guide.couchdb.org/draft/btree.html
• http://www.mongodb.org/display/DOCS/Indexes

NoSQL is, however, too fragmented to give a definite "yes, all NoSQL systems need indexes", I believe. Most systems require and provide indexes but not at level most SQL databases do. Recently, the Cassandra people were proudly introducing secondary indexes, i.e., more than a single clustered index.

• http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes (well, not so recently as I remember)

Answer 2

Definitely nosql databases need index,

i.e. but in most popular databases you need not to maintain index by yourself because as per current needs of nosql databases communities of nosql databases is developing with new features and with "Code Less, Get More"