Super column

File:SuperColumn (data store).png

The super column consists of a (unique) super column name, and a number of columns.

A super column is a tuple (a pair) with a binary super column name and a value that maps it to many columns. They consist of a key-value pairs, where the values are columns. Theoretically speaking, super columns are (sorted) associative array of columns. Similar to a regular column family where a row is a sorted map of column names and column values, a row in a super column family is a sorted map of super column names that maps to column names and column values.

A super column is part of a keyspace (data model) together with other super columns and column families, and columns.

Code example

Written in the JSON-like syntax, a super column definition can be like this:

 {
   "mccv": {
     "Tags": {
       "cassandra": {
         "incubator": {"url": "http://incubator.apache.org/cassandra/"},
         "jira": {"url": "http://issues.apache.org/jira/browse/CASSANDRA"}
       },
       "thrift": {
         "jira": {"url": "http://issues.apache.org/jira/browse/THRIFT"}
       }
     }
   }
 }

See also

• Column (data store)
• Keyspace (NoSQL)

External links

• The Apache Cassandra data model