Super column
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A super column is a tuple (a pair) with a binary super column name and a value that maps it to many columns.[1] They consist of a key–value pairs, where the values are columns. Theoretically speaking, super columns are (sorted) associative array of columns.[2] 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 together with other super columns and column families, and columns.
Code example[edit]
Written in the JSON-like syntax, a super column definition can be like this:
{ "databases": { "Cassandra": { "age": 20, "name": { "firstName": "Cassandra", "lastName": "apache" } }, "HBase": { "age": 20, "address": { "city": "Seoul", "postcode": "1234" } } } } Where:
"databases" are keyspace;
"Cassandra" and "HBase" are rowKeys;
"name" and "address" are super column names;
"firstName", "city", "age", etc. are column names.
See also[edit]
References[edit]
- ^ Sarkissian, Arin (September 1, 2009). "WTF is a SuperColumn". arin.me. Retrieved October 28, 2017.
A SuperColumn is a tuple w/ a binary name & a value which is a map containing an unbounded number of Columns - keyed by the Column's name.
- ^ Ellis, Jonathan (August 15, 2016). "Data Model". Apache Cassandra Wiki. Retrieved October 28, 2017.
External links[edit]
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