What is MultiValue Database?

• What is MultiValue Database?

MultiValue is a type of NoSQL and multidimensional database, typically considered synonymous with PICK, a database originally developed as the Pick operating system.
These databases differ from a relational database in that they have features that support and encourage the use of attributes which can take a list of values, rather than all attributes being single-valued.
Unlike SQL-DBMS tools, most MultiValue databases can be accessed both with or without SQL.

Data model example
In a MultiValue database system:
a Database is called an "Account"
a Table is called a "file"
a Column is an "Attribute" or "Dictionary": attributes generally point at raw data, while dictionaries apply some transformation to the raw data

For example, assume there's a file (table) called "PERSON". And in this file there is a Dictionary (column) called "eMailAddress". The eMailAddress field can store a variable number of email address values in the single record.
So the list [joe@abc132.info, jdb@gbmail.net, joe_bacde@thisorthat.edu] can be stored and accessed via a single query / disk read when accessing the associated record.

To achieve the same (1-to-many) relationship within a Relational Database system one would be required to create an additional table to store the variable number of email Addresses associated to a single "PERSON" record.
http://en.wikipedia.org/wiki/MultiValue