Cassandra and unstructured data

Question

I\'m relatively new to NoSQL, but I\'ve done a fair bit of toying with relational databases.

We are evaluating Cassandra for use in an environment where our data mod

Answer 1

Unstructured means that you have a schema-less column family. Each row has (obviously) a row-key. But the rest of each row can contain arbitrary key/value pairs - even the data types do not need to match between rows.

But as trulite correctly notes, it is a generally a bad idea to use a schema-less data model. Look at http://planetcassandra.org/blog/post/the-myth-of-schema-less/

Answer 2

Cassandra can at best be searchable for semi-structured data. That too via use of clustering keys and secondary indexes. Clustering keys is definitely an efficient way for searching semi-structured data.

Searching secondary indexed data without specifying the partition key is not efficient. There a few solutions which help help here namely DSE Search(Solr with Cassandr) and Stargate. Both of these solutions may also help in case one of the columns is unstructured text.

Otherwise it isn't a great idea to do unstructured data with Cassandra as it may not be searchable without a key.