Let’s start with the definition of a wide column database.
Its architecture uses (a) persistent, sparse matrix, multi-dimensional
mapping (row-value, column-value, and timestamp) in a tabular format
meant for massive scalability (over and above the petabyte scale).
A relational database is designed to maintain the relationship between the entity and the columns that describe the entity. A good example is a Customer table. The columns hold values describing the Customer’s name, address, and contact information. All of this information is the same for each and every customer.
A wide column database is one type of NoSQL database.
Maybe this is a better image of four wide column databases.
My understanding is that the first image at the top, the Column model, is what we called an entity/attribute/value table. It’s an attribute/value table within a particular entity (column).
For Customer information, the first wide-area database example might look like this.
Customer ID Attribute Value
----------- --------- ---------------
100001 name John Smith
100001 address 1 10 Victory Lane
100001 address 3 Pittsburgh, PA 15120
Yes, we could have modeled this for a relational database. The power of the attribute/value table comes with the more unusual attributes.
Customer ID Attribute Value
----------- --------- ---------------
100001 fav color blue
100001 fav shirt golf shirt
Any attribute that a marketer can dream up can be captured and stored in an attribute/value table. Different customers can have different attributes.
The Super Column model keeps the same information in a different format.
Customer ID: 100001
Attribute Value
--------- --------------
fav color blue
fav shirt golf shirt
You can have as many Super Column models as you have entities. They can be in separate NoSQL tables or put together as a Super Column family.
The Column Family and Super Column family simply gives a row id to the first two models in the picture for quicker retrieval of information.