{{Short description, A database project that organizes data in packed columns
A column family is a database object that contains columns of related data. It is a
tuple
In mathematics, a tuple is a finite ordered list (sequence) of elements. An -tuple is a sequence (or ordered list) of elements, where is a non-negative integer. There is only one 0-tuple, referred to as ''the empty tuple''. An -tuple is defi ...
(pair) that consists of a key–value pair, where the key is mapped to a value that is a set of columns. In analogy with relational databases, a column family is as a "table", each key-value pair being a "row". Each column is a
tuple
In mathematics, a tuple is a finite ordered list (sequence) of elements. An -tuple is a sequence (or ordered list) of elements, where is a non-negative integer. There is only one 0-tuple, referred to as ''the empty tuple''. An -tuple is defi ...
( triplet) consisting of a column name, a value, and a
timestamp
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolut ...
database table
A table is a collection of related data held in a table format within a database. It consists of columns and rows.
In relational databases, and flat file databases, a ''table'' is a set of data elements (values) using a model of vertical colum ...
, this data would be grouped together within a table with other non-related data.
Two types of column families exist:
* Standard column family: contains only columns
* Super column family: contains a map of super columns